Polyphenolic hydroxyl fatty alkyl amide lubricant for water-based drilling fluid and preparation method of polyphenol hydroxyl fatty alkyl amide lubricant

Abstract

The invention discloses a polyphenol hydroxyl fatty alkyl amide lubricant for water-based drilling fluid and a preparation method of the polyphenol hydroxyl fatty alkyl amide lubricant, and belongs to the technical field of oilfield chemistry, the preparation method comprises the following steps: a, weighing 0.10 mol of polyhydroxybenzoic acid, 0.10-0.12 mol of fatty amine and 0.3-0.5% of a catalyst NaF; b, adding into a 250mL three-neck flask provided with a condensation reflux device and a water segregator, introducing nitrogen for protection, heating to 200-250 DEG C, and stirring for reaction for 5-7 hours to obtain a dark brown viscous liquid product; c, carrying out amidation reaction on polyhydroxybenzoic acid and fatty amine to generate polyphenol hydroxyl fatty alkyl amide; and d, stirring and mixing the polyphenol hydroxyl fatty alkyl amide and the solvent high-carbon-number fatty alcohol according to the mass ratio of 6: 4-4: 6 at 70-80 DEG C for 2-3 hours to obtain the lubricant product. The lubricant prepared by the invention has strong adsorption capacity at high temperature and high salt, and a formed lubricating film has strong extreme pressure resistance and wear resistance and is suitable for efficient drilling of ultra-deep wells.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield chemistry, in particular to a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and a preparation method thereof. Background Art

[0002] The lubrication performance of drilling fluid is a key factor affecting the torque and friction of drilling construction, and plays a vital role in ensuring drilling safety and efficiency. With the exploration and development of deep and ultra-deep oil and gas resources receiving more attention, the drilling operations of deep and ultra-deep wells have been increasing in recent years, but the problems of high torque and high friction have become more and more prominent, seriously affecting the mechanical drilling speed, and even leading to complex situations such as pressure support, drill bit sticking or drill tool damage. In addition, the drilling conditions of deep and ultra-deep wells are harsh, with high temperature, high pressure and high salt harsh environment, which puts extremely high requirements on the lubrication performance of drilling fluid. Adding lubricants to drilling fluid is the main technical means to improve lubrication performance. Currently, commonly used lubricants include graphite powder, plastic pellets, mineral oil, vegetable oil, crude oil, surfactants and fatty acid esters and their derivatives. Among them, mixing graphite powder, plastic pellets, mineral oil, vegetable oil and crude oil into drilling fluid has limited lubrication effect and cannot meet the needs of reducing friction and drag in ultra-deep wells. Surfactants such as octylphenol polyoxyethylene ether and fatty acid esters such as methyl oleate have a certain lubricating effect, but because they are difficult to adsorb firmly on the surface of drill tools under high temperature and high salt conditions, the lubricating film formed is thin and has poor wear resistance. Therefore, the friction and drag reduction capabilities need to be further improved, and it is difficult to meet the needs of efficient drilling of ultra-deep wells.

[0003] A Chinese patent document with publication number CN110343562A and publication date October 18, 2019 discloses a water-based special fatty amine high-efficiency lubricant, characterized in that it comprises the following components in parts by weight: 5 to 15 of special fatty amine, 1 to 5 of acetic acid, 1 to 5 of alkyl dimethyl tertiary amine, 0.1 to 1 of bactericide, 0.1 to 1 of antibacterial agent, 0.5 to 5 of rust inhibitor, 1 to 5 of surfactant, 0.5 to 5 of dispersant, and soft water. The special fatty amine is selected from any one of N-dodecyl-1,3-propylenediamine, N-dodecyl-1,3-propylenediamine, N-tetradecyl-1,3-propylenediamine, N-hexadecyl-1,3-propylenediamine, N-octadecyl-1,3-propylenediamine, N-oleyl-1,3-propylenediamine and N-tallow-1,3-propylenediamine, or a mixture of two or more thereof in any proportion.

[0004] The water-based special fatty amine high-efficiency lubricant disclosed in the patent document can significantly reduce the friction between the packaging container bottle or can and the conveyor belt, and can fully meet the needs of the modern food industry production line. However, the adsorption capacity is weak under high temperature and high salt, and the lubricating film formed has poor extreme pressure and wear resistance, which is not suitable for ultra-deep well high-efficiency drilling. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the present invention provides a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and a preparation method thereof. The present invention has strong adsorption capacity under high temperature and high salt, and the formed lubricating film has strong extreme pressure and wear resistance, and is suitable for ultra-deep well efficient drilling.

[0006] The present invention is achieved through the following technical solutions: The invention discloses a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid, which is characterized by comprising polyhydroxybenzoic acid, fatty amine and high-carbon fatty alcohol.

[0007] The method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid is characterized by comprising the following steps: a. Weigh 0.10 mol of polyhydroxybenzoic acid, 0.10-0.12 mol of fatty amine and 0.3-0.5% of catalyst NaF; b. Add to a 250 mL three-necked flask equipped with a condensation reflux device and a water separator, pass nitrogen protection, heat to 200-250°C, stir and react for 5-7 hours to obtain a dark brown viscous liquid product; c. Polyhydroxybenzoic acid and fatty amine undergo amidation reaction to generate polyphenol hydroxy fatty alkyl amide; d. Mix the polyphenol hydroxy fatty alkyl amide and the solvent high carbon number fatty alcohol in a mass ratio of 6:4 to 4:6 at 70 to 80° C. for 2 to 3 hours to obtain a lubricant product.

[0008] In the step a, 0.3-0.5% of the catalyst NaF refers to the proportion relative to the total mass of the synthetic raw materials.

[0009] In the step a, the polyhydroxybenzoic acid is 3,4-dihydroxybenzoic acid.

[0010] In the step a, the polyhydroxybenzoic acid is 2,3-dihydroxybenzoic acid.

[0011] In the step a, the polyhydroxybenzoic acid is 3,4,5-trihydroxybenzoic acid.

[0012] In the step a, the polyhydroxybenzoic acid is 2,3,4-trihydroxybenzoic acid.

[0013] In the step a, the fatty amine is octadecyl primary amine, oleyl primary amine, hexadecyl primary amine or dioctadecyl secondary amine.

[0014] In the step d, the high carbon number fatty alcohol is octadecenol.

[0015] In the step d, the high carbon number fatty alcohol is n-dodecanol.

[0016] The basic principles of the present invention are as follows: The preparation of polyphenol hydroxy fatty alkyl amide lubricant is carried out in two steps. The first step is to carry out an amidation reaction between polyhydroxybenzoic acid and a long-chain fatty amine at a high temperature to generate an amidation product. The second step is to dissolve the amidation product in a high-carbon fatty alcohol and mix them evenly to finally obtain a lubricant product.

[0017] The key to the excellent performance of lubricant molecules is that they can not only be effectively adsorbed on the surface of metal drill tools and wellbore rocks, but also have suitable lipophilic long chains, which can then form a thick and wear-resistant oil film, converting the solid-solid friction between the drill tools and the wellbore into friction between the oil films. Lubricants are strongly adsorbed amphiphilic molecules with non-ionic structures that are insensitive to electrolytes and pH. There are no ester or ether bonds in the structure that are easily broken at high temperatures, and thus have good resistance to high temperatures, salts and calcium.

[0018] The beneficial effects of the present invention are mainly manifested in the following aspects: 1. The lubricant of the present invention is a specific component of polyhydroxybenzoic acid, fatty amine and high-carbon fatty alcohol, which has stronger adsorption capacity and good high temperature resistance and salt and calcium resistance compared with the prior art.

[0019] 2. The present invention comprises the following steps: a. weighing 0.10 mol of polyhydroxybenzoic acid, 0.10-0.12 mol of fatty amine and 0.3-0.5% of catalyst NaF; b. adding the mixture into a 250 mL three-necked flask equipped with a condensation reflux device and a water separator, passing nitrogen gas for protection, heating to 200-250° C., and stirring for reaction for 5-7 hours to obtain a dark brown viscous liquid product; c. amidation reaction of polyhydroxybenzoic acid and fatty amine to generate polyphenol hydroxy fatty alkyl amide; d. stirring and mixing polyphenol hydroxy fatty alkyl amide and solvent high carbon number fatty alcohol at a mass ratio of 6:4-4:6 at 70-80° C. for 2-3 hours to obtain a lubricant product. Compared with the prior art, the prepared lubricant has a strong adsorption capacity at high temperature and high salt, and the formed lubricating film has strong extreme pressure and wear resistance, and is suitable for efficient drilling of ultra-deep wells.

[0020] 3. The present invention is based on the principle that the polyphenol hydroxyl structure can form metal coordination bonds with metal drill tools and multiple hydrogen bonds with rock and clay surfaces, thereby greatly improving the adsorption capacity of the lubricant under high temperature and high salt conditions, replacing ester bonds and ether bonds with amide bonds with better temperature resistance, and introducing a benzene ring structure, thereby effectively improving the thermal stability of the lubricant.

[0021] 4. The nonionic strong adsorption amphiphilic molecular lubricant of the present invention overcomes the problems of weak adsorption capacity, insufficient high temperature and salt and calcium resistance, and unsatisfactory lubrication and drag reduction effect of existing synthetic ester lubricants, and can effectively solve the problems of high torque and high friction in deep and ultra-deep well drilling construction.

[0022] 5. Compared with existing solid and synthetic fatty acid ester lubricants, the present invention has better lubrication effect and excellent resistance to temperature, salt and calcium, with a temperature resistance of more than 220°C, a salt resistance of 30%, and a calcium resistance of 30%.

[0023] 6. The present invention has no negative impact on the rheological and filtration properties of the drilling fluid, and has a certain viscosity reduction effect, which is beneficial to reducing the circulation pressure loss of the drilling fluid and plays a drag reduction effect.

[0024] 7. In the whole preparation process of the present invention, the amount of raw materials added is small and the effect is obvious; it is non-toxic and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 Schematic diagram of the effect of aging temperature on the lubrication performance of lubricant CQRHJ-1; Figure 2 Schematic diagram of the effect of NaCl and CaCl2 intrusion on the lubrication performance of lubricant CQRHJ-1. DETAILED DESCRIPTION

[0026] Example 1 The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid comprises polyhydroxybenzoic acid, fatty amine and high carbon number fatty alcohol.

[0027] This embodiment is the most basic implementation method. The lubricant is a specific component of polyhydroxybenzoic acid, fatty amine and high-carbon fatty alcohol. Compared with the prior art, it has stronger adsorption capacity and good high temperature and salt and calcium resistance.

[0028] Example 2 The method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid comprises the following steps: a. Weigh 0.10 mol of 3,4-dihydroxybenzoic acid, 0.10 mol of octadecyl primary amine and 0.3% catalyst NaF; b. Add the mixture into a 250 mL three-necked flask equipped with a condensing reflux device and a water separator, pass nitrogen gas for protection, heat to 200°C in an oil bath, stir and react for 5 hours to obtain a dark brown viscous liquid product; c. 3,4-dihydroxybenzoic acid and octadecyl primary amine undergo amidation reaction to generate bisphenol hydroxyoctadecyl amide; d. The amidation product obtained in the previous step and the solvent octadecenol were stirred and mixed at a mass ratio of 5:5 at 70° C. for 3 h to obtain the lubricant product CQRHJ-1.

[0029] This embodiment is a preferred implementation method. Compared with the prior art, the prepared lubricant has strong adsorption capacity under high temperature and high salt conditions, and the lubricating film formed has strong resistance to extreme pressure and wear, and is suitable for efficient drilling of ultra-deep wells.

[0030] Example 3 The method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid comprises the following steps: a. Weigh 0.10 mol of 2,3-dihydroxybenzoic acid, 0.12 mol of oleyl primary amine and 0.3% catalyst NaF; b. Add the mixture into a 250 mL three-necked flask equipped with a condensing reflux device and a water separator, pass nitrogen gas for protection, heat to 210°C in an oil bath, stir and react for 6 hours to obtain a dark brown viscous liquid product; c. 2,3-dihydroxybenzoic acid and oleyl primary amine undergo amidation reaction to generate bisphenol hydroxyoctadecene amide; d. The amidation product obtained in the previous step and the solvent octadecenol were stirred and mixed at a mass ratio of 6:4 at 75° C. for 2.5 hours to obtain the lubricant product CQRHJ-2.

[0031] This embodiment is a preferred implementation method. Based on the principle that the polyphenol hydroxyl structure can form metal coordination bonds with metal drill tools and multiple hydrogen bonds with rock and clay surfaces, the adsorption capacity of the lubricant under high temperature and high salt conditions is greatly improved, and ester bonds and ether bonds are replaced by amide bonds with better temperature resistance, and a benzene ring structure is introduced, thereby effectively improving the thermal stability of the lubricant.

[0032] Example 4 The method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid comprises the following steps: a. Weigh 0.10 mol of 3,4,5-trihydroxybenzoic acid, 0.11 mol of hexadecyl primary amine and 0.4% catalyst NaF b. Add the mixture into a 250 mL three-necked flask equipped with a condensing reflux device and a water separator, pass nitrogen gas for protection, heat to 250°C in an oil bath, stir and react for 5 hours to obtain a dark brown viscous liquid product; c. 3,4,5-Trihydroxybenzoic acid and hexadecyl primary amine undergo amidation reaction to generate triphenol hydroxy hexadecyl amide d. The amidation product obtained in the previous step and the solvent n-dodecanol were stirred and mixed at a mass ratio of 4:6 at 80° C. for 2 h to obtain the lubricant product CQRHJ-3.

[0033] This embodiment is another preferred implementation method. The non-ionic strong adsorption amphiphilic molecular lubricant overcomes the problems of weak adsorption capacity, insufficient high temperature and salt and calcium resistance, and unsatisfactory lubrication and drag reduction effect of existing synthetic ester lubricants. It can effectively solve the problems of high torque and high friction in deep and ultra-deep well drilling construction.

[0034] Example 5 The method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid comprises the following steps: a. Weigh 0.10 mol of 2,3,4-trihydroxybenzoic acid, 0.12 mol of dioctadecyl secondary amine and 0.5% catalyst NaF; b. Add the mixture into a 250 mL three-necked flask equipped with a condensation reflux device and a water separator, pass nitrogen gas, heat to 210°C in an oil bath, and stir for 7 hours to obtain a dark brown viscous liquid product. c. 2,3,4-trihydroxybenzoic acid and dioctadecyl secondary amine undergo an amidation reaction to generate triphenol hydroxy dioctadecyl amide; d. The amidation product obtained in the previous step and the solvent octadecenol were stirred and mixed at a mass ratio of 4:6 at 80° C. for 2 h to obtain the lubricant product CQRHJ-4.

[0035] This embodiment is the best implementation method. Compared with existing solid and synthetic fatty acid ester lubricants, it has better lubrication effect and excellent resistance to temperature, salt and calcium. It can resist temperature greater than 220°C, resist salt by 30%, and resist calcium by 30%.

[0036] It has no negative impact on the rheological and filtration properties of drilling fluid, and has a certain viscosity reduction effect, which is beneficial to reducing the circulating pressure loss of drilling fluid and playing a drag reduction effect.

[0037] During the entire preparation process, the amount of raw materials added is small and the effect is obvious; it is non-toxic and environmentally friendly.

[0038] The lubricating properties of the four prepared polyphenol hydroxy fatty alkyl amide lubricants are evaluated below: The evaluation slurry is a 4% bentonite-based slurry, and the aging conditions are 200°C and 16h. The extreme pressure lubrication coefficients of four polyphenol hydroxy fatty alkyl amide lubricants and foreign products DFL, CNOOC oilfield services product PF-Lube and methyl oleate before and after aging in 4% base slurry are shown in Table 1. Table 1 shows the lubrication coefficients of different lubricants before and after aging in base slurry.

[0039] Table 1 As can be seen from Table 1, the four prepared polyphenol hydroxy fatty alkyl amide lubricants all showed excellent lubrication effects before and after high-temperature aging at 200°C, with extreme pressure lubrication coefficients lower than 0.08, and lubrication coefficient reduction rates always greater than 85%. At the same time, under the same conditions, their lubrication effects were better than those of foreign products DFL, CNOOC Oilfield Services product PF-Lube and methyl oleate, indicating that they have good high-temperature resistance and lubrication properties.

[0040] The polyphenol hydroxy fatty alkyl amide lubricant CQRHJ-1 was used to further evaluate its high temperature and salt calcium resistance. The addition amount was 1%. The experimental results are as follows: Figure 1 and Figure 2 As shown. Figure 1 It can be seen that with the increase of aging temperature, the reduction rate of lubrication coefficient is always greater than 85%, and even after aging at 220℃, it is still as high as 85.4%, indicating that the temperature resistance of CQRHJ-1 can reach at least 220℃. Figure 2 It can be seen that the extreme pressure lubrication coefficient reduction rate of the base slurry containing 1% CQRHJ-1 was always greater than 80% after being contaminated by 30% NaCl and 30% CaCl2 and aged at 220°C, indicating that it has excellent high temperature and salt and calcium resistance lubrication properties.

[0041] The above experiments show that the polyphenol hydroxy fatty alkyl amide lubricant CQRHJ-1 has excellent high temperature resistance, salt resistance and calcium resistance lubrication performance.

[0042] The lubricating effect of the lubricant was further evaluated in a high-temperature and high-density water-based drilling fluid system. Drilling fluid formula: 1% base slurry + 0.5% NaOH + 0.3% polymer viscosity reducer + 0.8% polymer fluid loss reducer + 3% KFT + 2% SMP-3 + 4% SPNH + 5% KCl + 3% polymer plugging agent + 5% sulfonated asphalt + 0.5% sodium sulfite + 4% calcium carbonate + barite, density 2.2g / cm 3 The viscosity reduction effect was further evaluated and the results are shown in Table 2. Table 2 shows the effect of lubricant CQRHJ-1 on the performance of high-temperature and high-density water-based drilling fluid system.

[0043] Table 2 It can be seen from Table 2 that after adding the polyphenol hydroxy fatty alkyl amide lubricant CQRHJ-1, the rheological and filtration properties of the high-density drilling fluid before and after aging at 200°C did not deteriorate, and it had a slight viscosity reduction effect. The extreme pressure lubrication coefficient and the filter cake viscosity coefficient were greatly reduced to 0.122 and 0.0699, respectively, with a reduction rate of 40.2% and 56.2%, respectively. This shows that the lubricant CQRHJ-1 has a good lubrication effect in the high-temperature and high-density drilling fluid system and has no negative impact on the basic properties of the drilling fluid.

Claims

1. A polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid, characterized in that: Including polyhydroxybenzoic acids, fatty amines and high-carbon fatty alcohols.

2. A method for preparing a polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid, characterized in that: The following steps are involved: a. Weigh 0.10 mol of polyhydroxybenzoic acid, 0.10-0.12 mol of fatty amine and 0.3-0.5% of catalyst NaF; b. Add to a 250 mL three-necked flask equipped with a condensation reflux device and a water separator, pass nitrogen protection, heat to 200-250°C, stir and react for 5-7 hours to obtain a dark brown viscous liquid product; c. Polyhydroxybenzoic acid and fatty amine undergo amidation reaction to generate polyphenol hydroxy fatty alkyl amide; d. Mix the polyphenol hydroxy fatty alkyl amide and the solvent high carbon number fatty alcohol in a mass ratio of 6:4 to 4:6 at 70 to 80° C. for 2 to 3 hours to obtain a lubricant product.

3. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, 0.3-0.5% of the catalyst NaF refers to the proportion relative to the total mass of the synthetic raw materials.

4. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, the polyhydroxybenzoic acid is 3,4-dihydroxybenzoic acid.

5. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, the polyhydroxybenzoic acid is 2,3-dihydroxybenzoic acid.

6. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, the polyhydroxybenzoic acid is 3,4,5-trihydroxybenzoic acid.

7. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, the polyhydroxybenzoic acid is 2,3,4-trihydroxybenzoic acid.

8. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step a, the fatty amine is octadecyl primary amine, oleyl primary amine, hexadecyl primary amine or dioctadecyl secondary amine.

9. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step d, the high carbon number fatty alcohol is octadecenol.

10. The polyphenol hydroxy fatty alkyl amide lubricant for water-based drilling fluid and the preparation method thereof according to claim 2, characterized in that: In the step d, the high carbon number fatty alcohol is n-dodecanol.

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