Lubricant for drilling fluid and preparation method and application thereof

Abstract

The invention discloses a lubricant for drilling fluid and a preparation method and application thereof, and belongs to the field of petroleum drilling engineering. The lubricant includes: a) polyoctadecenoic acid ester; b) fatty acid ester: the product of vegetable oil and polyethylene glycol ester exchange. The preparation method is: physically mixing the polycondensation product of octadecenoic acid and mixed fatty alcohol with polyethylene glycol-modified vegetable oil. When applied in drilling fluid, the lubricant improves the lubrication performance and anti-wear performance of the lubricant, increases environmental protection, and ensures the long-term stability of the lubrication performance and anti-wear performance; at the same time, the preparation method is simplified, the production cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of petroleum drilling engineering, and more specifically, relates to a lubricant for drilling fluid and a preparation method and application thereof. Background Art

[0002] In the field of chemical synthesis, the research and development of lubricants has always been one of the important research directions. Especially in the field of oil drilling engineering, due to the particularity and complexity of the drilling operation environment, the lubrication performance of drilling fluid is extremely high. Drilling fluid not only needs to have good lubrication performance to reduce the friction between the drill bit and the well wall, reduce energy consumption, and improve drilling efficiency, but also needs to have good anti-wear performance to extend the service life of the drill bit. In the field of lubricant additives, fatty acid amide compounds are widely used in various lubricants due to their excellent lubrication and anti-wear properties. These compounds are usually prepared by chemical reactions of fatty acids and alcohols. In addition, vegetable oil, as a renewable resource, is also used to prepare lubricants due to its good biodegradability and environmental protection.

[0003] For example, the patent application document with Chinese patent application number 202210579791.2 and application publication date July 29, 2022 discloses a polymer brush lubricant for water-based drilling fluid, preparation method and application. The method comprises the steps of: mixing short-chain acrylate, long-chain acrylate and polar acrylate and dissolving them in base oil, wherein the base oil is one or a combination of two or more of mineral oil, synthetic oil and vegetable oil, and then adding a molecular weight regulator; adding an initiator under a nitrogen atmosphere to react; after the reaction is completed, naturally cooling to room temperature to obtain a polymer brush lubricant for water-based drilling fluid.

[0004] Although the existing technology has solved the problems of drilling fluid lubrication and anti-wear performance to a certain extent, there are still some shortcomings. First, the existing lubricant preparation methods are often complicated and have high production costs, which is a major limitation for large-scale industrial production. Secondly, although vegetable oils have good environmental protection, their lubrication and anti-wear properties are often not as good as chemically synthesized lubricants. Therefore, how to further improve the lubrication and anti-wear properties of lubricants while ensuring environmental protection is an important problem facing current technology. In addition, the existing technology may experience a decrease in lubrication and anti-wear properties during long-term use, which requires further research and improvement. Summary of the invention

[0005] 1. Problem to be solved

[0006] One of the purposes of the present invention is to provide a lubricant for drilling fluid, aiming to improve the lubricating performance and anti-wear performance of the lubricant while increasing environmental protection and ensuring the long-term stability of the lubricating performance and anti-wear performance.

[0007] Another object of the present invention is to provide a method for preparing a lubricant for drilling fluid, thereby simplifying the preparation method, reducing production costs, and improving production efficiency.

[0008] 2. Technical solution

[0009] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] According to the purpose of the present invention, the first aspect of the present invention provides a lubricant for drilling fluid, comprising:

[0011] a) polyoctadecenoic acid ester;

[0012] b) Fatty acid esters: products of transesterification of vegetable oils with polyethylene glycol.

[0013] When the above technical solution is adopted, the lubricant has the advantages of excellent lubrication performance, wide applicability, simple production process and easy industrialization.

[0014] As a possible implementation scheme, the mass ratio of polyoctadecenoic acid ester to fatty acid ester is (6-8):1.

[0015] As a possible implementation scheme, the polyoctadecenoic acid ester is a product of a polycondensation reaction between octadecenoic acid and a mixed fatty acid.

[0016] As a possible implementation scheme, the carbon chain length of the mixed fatty acid is 16 to 18, and the mixed fatty acid is preferably a mixture of hexadecanol and octadecanol (C16-C18) with a mixing mass ratio of 7:3; the hexadecanol product of Wuxi De Lami International Trading Co., Ltd. can be used.

[0017] When the above technical solution is adopted, the C16-C18 mixed alcohol and octadecenoic acid react to generate different products with obvious synergistic effect, which is better than mixed alcohols of a single carbon chain length and other carbon chain ranges.

[0018] As a possible implementation scheme, the feed mass ratio of octadecenoic acid to mixed fatty acids is 1:(2.4-3.2).

[0019] As a possible implementation scheme, the vegetable oil is soybean oil, cottonseed oil, castor oil, etc., preferably soybean oil, wherein the index in the vegetable oil is: solvent residue: ≤10 mg / kg.

[0020] As a possible implementation scheme, the brand of polyethylene glycol is PEG-1000. The industry uses molecular weight as the brand to distinguish brands, that is, PEG-1000 expresses that the polyethylene glycol is a brand with a molecular weight concentrated around 1000.

[0021] As a possible implementation scheme, the mass ratio of the vegetable oil and polyethylene glycol in the feed is (5.8-8.4):1.

[0022] The lubricant of the present invention has the following advantages:

[0023] 1) Improve lubrication and anti-wear performance: Although the existing technology has solved the problem of lubrication and anti-wear performance of drilling fluid to a certain extent, there is still the problem of insufficient lubrication and anti-wear performance. This technical solution greatly improves the lubrication and anti-wear performance by optimizing the composition and structure of the lubricant, meeting the lubrication performance requirements of the drilling fluid due to the particularity and complexity of the drilling operation environment.

[0024] 2) Balance of environmental protection, lubrication and anti-wear properties: Vegetable oil, as a renewable resource, is widely used in the preparation of lubricants due to its good biodegradability and environmental protection. However, the lubrication and anti-wear properties of vegetable oil are often inferior to those of chemically synthesized lubricants. This technical solution introduces grafted modified vegetable oil for auxiliary lubrication and improved anti-wear performance, thereby further improving the lubrication and anti-wear properties of the lubricant while ensuring environmental protection.

[0025] 3) Long-term stability of lubrication and anti-wear performance: The existing technology may suffer from the problem of reduced lubrication and anti-wear performance during long-term use. This technical solution improves the long-term stability of lubrication and anti-wear performance by optimizing the composition and structure of the lubricant, ensuring the smooth progress of drilling operations.

[0026] A second aspect of the present invention provides a method for preparing a lubricant for drilling fluid, the steps comprising:

[0027] S1, octadecenoic acid and mixed fatty alcohols undergo polycondensation reaction under the action of a catalyst to obtain polyoctadecenoic acid ester;

[0028] S2, transesterification reaction of vegetable oil and polyethylene glycol to obtain fatty acid esters;

[0029] S3, mixing the polyoctadecenoic acid ester of step S1 and the fatty acid ester of step S2 to obtain a lubricant for drilling fluid.

[0030] When the above technical scheme is adopted, step S1 is an alkyd condensation esterification reaction, in which a molecule of water is removed to generate an ester target product, which has the advantages of a long carbon chain and a stable structure. Experimental tests have shown that it has efficient lubrication and anti-wear properties; step S2 is an ester exchange reaction, in which high molecular weight polyethylene glycol and unsaturated vegetable oil esters are functionally exchanged to generate a modified vegetable oil containing polyethylene glycol functional groups, which greatly increases the hydrophilicity and molecular weight of the modified vegetable oil, and can effectively improve the long-term stability of the lubrication and anti-wear properties of this product while retaining its environmentally friendly degradation performance.

[0031] As a possible implementation scheme, in step S1, the carbon chain length of the mixed fatty acid is 16 to 18, and the mixed fatty acid is preferably a mixture of hexadecanol and octadecanol (C16-C18), and the mixing mass ratio is 7:3. The hexadecanol product of Wuxi De Lami International Trading Co., Ltd. can be used.

[0032] When the above technical solution is adopted, the C16-C18 mixed alcohol and octadecenoic acid react to generate different products with obvious synergistic effect, which is better than mixed alcohols of a single carbon chain length and other carbon chain ranges.

[0033] As a possible implementation scheme, in step S1, the mass ratio of the octadecenoic acid to the mixed fatty acids is 1:(2.4-3.2).

[0034] As a possible implementation scheme, in step S1, the catalyst is preferably sodium sulfate; the mass of sodium sulfate added is 1% to 3% of the mass of octadecenoic acid added.

[0035] As a possible implementation scheme, in step S1, the reaction pressure is controlled to be -0.5MPa to -0.7MPa. When the above technical scheme is adopted, a certain vacuum degree is maintained to promote the reversible esterification reaction in the forward reaction direction, while removing the generated water and side reaction products. Too high or too low vacuum degree will affect the progress of the reaction. Too low vacuum degree will lead to untimely forward reaction and increased side reactions, while too high vacuum degree will lead to loss of reaction products and blockage of pipelines.

[0036] As a possible implementation scheme, in step S1, the reaction temperature is controlled at 150°C ± 5°C; the reaction time is controlled at least 2 hours; after the reaction is completed, it is cooled to room temperature.

[0037] As a possible implementation scheme, in step S2, the vegetable oil is soybean oil, cottonseed oil, castor oil, etc., preferably soybean oil, wherein the index in the vegetable oil is: solvent residue: ≤10 mg / kg.

[0038] As a possible implementation scheme, in step S2, the brand of the polyethylene glycol is PEG-1000. The industry uses molecular weight as the brand to distinguish brands, that is, PEG-1000 expresses that the polyethylene glycol is a brand with a molecular weight concentrated around 1000.

[0039] As a possible implementation scheme, in step S2, the mass ratio of the vegetable oil and polyethylene glycol is (5.8-8.4):1.

[0040] As a possible implementation scheme, in step S2, the reaction temperature is controlled at 120°C ± 5°C; the reaction time is controlled at least 4 hours; after the reaction is completed, it is cooled to room temperature.

[0041] As a possible implementation scheme, in step S3, polyoctadecenoic acid ester and fatty acid ester are mixed by heating and stirring, the temperature is controlled at 85°C±5°C, the stirring time is 1.5 hours, and after the stirring is completed, it is cooled to room temperature.

[0042] As a possible implementation scheme, in step S3, the mass ratio of polyoctadecenoic acid ester to fatty acid ester is (6-8):1.

[0043] The preparation method of the present invention can solve the problems of cumbersomeness and high cost of the method: the existing lubricant preparation method is often cumbersome and has high production costs, which is a major limitation for large-scale industrial production. The technical solution uses octadecene acid and mixed fatty alcohols to prepare a high-efficiency ester lubricant, and introduces grafted modified vegetable oil for auxiliary lubrication and improved anti-wear performance, thereby simplifying the preparation method, reducing production costs, and improving production efficiency.

[0044] The second aspect of the present invention provides a drilling fluid, comprising the above lubricant, wherein the amount of the lubricant for drilling fluid in the drilling fluid is 1-5%.

[0045] 3. Beneficial effects

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention adopts octadecene acid and mixed fatty alcohols to prepare a high-efficiency ester lubricant by mixing and modifying: octadecene acid and mixed fatty alcohols are mixed and modified to prepare a high-efficiency ester lubricant. This method not only simplifies the preparation method, reduces production costs, and improves production efficiency, but also improves the lubricating performance and anti-wear performance of the lubricant.

[0048] (2) The present invention introduces grafted modified vegetable oil to assist lubrication and improve anti-wear performance: In the prepared ester lubricant, grafted modified vegetable oil is introduced to assist lubrication and improve anti-wear performance. The grafted modified vegetable oil not only has good biodegradability and environmental protection, but also has good lubrication and anti-wear performance, which can further improve the lubrication and anti-wear performance of the lubricant while ensuring environmental protection.

[0049] (3) The present invention optimizes the composition and structure of the lubricant: By optimizing the composition and structure of the lubricant, the long-term stability of the lubricating performance and anti-wear performance is improved, ensuring the smooth progress of the drilling operation. The optimized composition and structure not only improve the lubricating performance and anti-wear performance, but also improve the long-term stability of these properties, so that the lubricant can maintain good lubricating performance and anti-wear performance during use.

[0050] (4) The lubricant of the present invention not only has good lubrication performance, which can greatly reduce friction torque and improve the lubrication performance of drilling fluid, but also has good anti-wear performance, which can extend the service life of drilling tools.

[0051] (5) The lubricant of the present invention will not suffer from the problem of deterioration of lubrication performance and anti-wear performance during long-term use, and has good long-term stability, which cannot be guaranteed by the prior art.

[0052] (6) The present invention simplifies the preparation method of lubricants: by using octadecene acid and mixed fatty alcohols to prepare high-efficiency ester lubricants, and introducing grafted modified vegetable oils for auxiliary lubrication and improved anti-wear performance, the preparation method of lubricants is simplified, production costs are reduced, and production efficiency is improved. This simplified preparation method makes large-scale industrial production possible, improves production efficiency, and reduces production costs. It can be applied not only to the field of oil drilling engineering, but also to other fields that require high-efficiency lubrication and anti-wear performance, and has broad application prospects. DETAILED DESCRIPTION

[0053] The present invention is further described below in conjunction with specific embodiments.

[0054] In a specific embodiment, C16-C18 is a 16-octadecyl alcohol product of Wuxi De La Mi International Trading Co., Ltd., C12-C14 is a 12-tetradecanol product of Wuxi De La Mi International Trading Co., Ltd., C16 is a 16-octadecyl alcohol product of Wuxi De La Mi International Trading Co., Ltd., and C18 is an octadecyl alcohol product of Wuxi De La Mi International Trading Co., Ltd.

[0055] Example 1

[0056] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0057] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0058] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0059] S3: 50 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0060] Example 2

[0061] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0062] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0063] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0064] S3: 60 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0065] Example 3

[0066] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0067] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0068] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain the intermediate product fatty acid ester.

[0069] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0070] Example 4

[0071] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0072] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0073] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0074] S3: 80g of polyoctadecenoic acid ester and 10g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C±5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0075] Example 5

[0076] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0077] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0078] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0079] S3: 90 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0080] Example 6

[0081] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0082] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0083] S2: Mix 57 g soybean oil (solvent white oil residue ≤ 10 mg / kg) and 10 g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120°C ± 5°C, and react for 4 hours. After the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0084] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0085] Example 7

[0086] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0087] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0088] S2: Mix 58 g soybean oil (solvent white oil residue ≤ 10 mg / kg) and 10 g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120°C ± 5°C, and react for 4 hours. After the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0089] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0090] Example 8

[0091] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0092] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0093] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0094] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0095] Example 9

[0096] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0097] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0098] S2: 84 g soybean oil (solvent white oil residue ≤ 10 mg / kg) and 10 g polyethylene glycol were mixed and added to reactor B, stirring was started, the temperature was controlled at 120°C ± 5°C, the reaction time was 4 h, and after the reaction was completed, the mixture was cooled to room temperature to obtain fatty acid esters.

[0099] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0100] Example 10

[0101] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0102] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0103] S2: 85 g soybean oil (solvent white oil residue ≤ 10 mg / kg) and 10 g polyethylene glycol were mixed and added to reactor B, stirring was started, the temperature was controlled at 120°C ± 5°C, the reaction time was 4 h, and after the reaction was completed, the mixture was cooled to room temperature to obtain fatty acid esters.

[0104] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0105] Embodiment 11

[0106] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0107] S1: 25g of octadecenoic acid, 57.5g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0108] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0109] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0110] Example 12

[0111] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0112] S1: 25g of octadecenoic acid, 60g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0113] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0114] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0115] Embodiment 13

[0116] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0117] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0118] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0119] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0120] Embodiment 14

[0121] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0122] S1: 25g of octadecenoic acid, 80g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0123] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0124] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0125] Embodiment 15

[0126] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0127] S1: 25g of octadecenoic acid, 82.5g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0128] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0129] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0130] Example 16

[0131] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0132] S1: 25g of octadecenoic acid, 70g of C12-C14 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0133] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, reaction time 4h, after the reaction is completed, cool to room temperature, fatty acid ester.

[0134] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0135] Embodiment 17

[0136] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0137] S1: 25g of octadecenoic acid, 70g of C16 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0138] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0139] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0140] Embodiment 18

[0141] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0142] S1: 25g of octadecenoic acid, 70g of C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150°C±5°C, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0143] S2: Mix 70g soybean oil (solvent white oil residue ≤10mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0144] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0145] Embodiment 19

[0146] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0147] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0148] S2: Mix 70g soybean oil (solvent white oil residue 15mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, reaction time 4h, after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0149] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0150] Embodiment 20

[0151] This embodiment provides a method for preparing a lubricant for drilling fluid, and the specific steps are as follows:

[0152] S1: 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate were mixed and added into reactor A, stirring was started, the temperature was controlled at 150℃±5℃, the reaction pressure was controlled at -0.5~-0.7MPa, the reaction was carried out for 2h, and after the reaction was completed, the mixture was cooled to room temperature to obtain polyoctadecenoic acid ester.

[0153] S2: Mix 70g soybean oil (solvent white oil residue 20mg / kg) and 10g polyethylene glycol and add them to reactor B, start stirring, control the temperature at 120℃±5℃, react for 4h, and after the reaction is completed, cool to room temperature to obtain fatty acid esters.

[0154] S3: 70 g of polyoctadecenoic acid ester and 10 g of fatty acid ester were mixed and added into a reactor with stirring. The temperature was controlled at 85°C ± 5°C for 1.5 hours. After the stirring was completed, the mixture was cooled to room temperature to obtain a lubricant for drilling fluid.

[0155] Comparative Example 1

[0156] The lubricant preparation method of this comparative example is basically the same as that of Example 3, except that octadecenoic acid is replaced by hexadecenoic acid.

[0157] Comparative Example 2

[0158] The lubricant preparation method of this comparative example is basically the same as that of Example 3, except that the reaction temperature in step S1 is reduced by 10°C.

[0159] Comparative Example 3

[0160] The lubricant preparation method of this comparative example is basically the same as that of Example 3, except that the reaction pressure in step S1 is -0.2 to -0.5 MPa.

[0161] Comparative Example 4

[0162] The lubricant preparation method of this comparative example is basically the same as that of Example 3, except that the reaction time in step S2 is shortened to 2 hours.

[0163] Comparative Example 5

[0164] This comparative example provides a method for preparing a lubricant, and the specific steps are as follows:

[0165] Mix 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate and add them into reactor A. Start stirring, control the temperature at 150℃±5℃, control the reaction pressure at -0.5~-0.7MPa, react for 2h, and after the reaction is completed, cool to room temperature to obtain a lubricant.

[0166] Comparative Example 6

[0167] This comparative example provides a method for preparing a lubricant, and the specific steps are as follows:

[0168] Step 1: Add 25g of octadecenoic acid, 70g of C16-C18 and 0.5g of sodium sulfate to reactor A, start stirring, control the temperature at 150°C±5°C, control the reaction pressure at -0.5~-0.7MPa, react for 2h, and after the reaction is completed, cool to room temperature to obtain the intermediate product polyoctadecenoic acid ester.

[0169] Step 2: Mix 70g of polyoctadecenoic acid ester and 10g of soybean oil and add them into the reactor to stir. Control the temperature at 85℃±5℃ for 1.5 hours. After stirring, cool to room temperature to obtain a lubricant.

[0170] Performance Testing

[0171] The lubricants prepared in the embodiments and comparative examples were added to different drilling fluid systems of a drilling company in Karamay, Xinjiang at a ratio of 1% (drilling fluid 1: high-quality low-solid polymer system; drilling fluid 2: polysulfonated mixed oil system; drilling fluid 3: polysulfonated anti-collapse system; drilling fluid 4: solid-free system) for performance evaluation tests. The product performance was evaluated by the lubrication coefficient reduction rate and torque reduction rate to evaluate the lubricant's effect on the lubrication performance and anti-wear performance of the base slurry. The lubrication coefficient reduction rate was tested to be more than 90%, and the torque reduction rate was more than 80%; among them:

[0172] 1) Lubrication coefficient reduction rate test method: The test is carried out in accordance with the requirements of the petroleum and natural gas industry standard SY / T 6094-94.

[0173] 2) Torque reduction rate test method: The test is carried out in accordance with the requirements of the petroleum and natural gas industry standard SY / T 6094-94.

[0174] in addition,

[0175] Environmental protection is tested using the BOD5 / CODCr biodegradable performance evaluation method.

[0176] CODCr test method: Test according to the requirements of GB11914-89.

[0177] BOD5 test method: Test according to the requirements of HJ 505-2009.

[0178] The results of the above test items are shown in Table 1 below:

[0179] Table 1 Test results of lubricants prepared in various embodiments and comparative examples

[0180]

[0181]

[0182]

[0183] From the above embodiments and comparative examples, the present invention can be widely used in the fields of chemical synthesis, oil drilling engineering and lubricant additives. In the field of chemical synthesis, the present invention provides a lubricant for drilling fluid and a preparation method thereof, which is simple and easy to operate, has low production cost and has good industrial application prospects. At the same time, since the lubricant has excellent lubrication and anti-wear properties, it can greatly reduce friction torque and improve the lubrication performance of drilling fluid, so it has broad application prospects in the field of oil drilling engineering. In the field of oil drilling engineering, the lubricant provided by the technical solution can not only meet the requirements of the drilling operation environment for lubrication performance, but also because of its good anti-wear performance, it can extend the service life of the drill, improve drilling efficiency, and reduce energy consumption, so it has broad application prospects in the field of oil drilling engineering. In the field of lubricant additives, the present invention introduces grafted modified vegetable oil for auxiliary lubrication and improvement of anti-wear performance, which can not only improve the lubrication and anti-wear performance of the lubricant, but also because the vegetable oil has good biodegradability and environmental protection, so the technical solution has broad application prospects in the field of lubricant additives. In general, the present invention can not only meet the current market demand for efficient and environmentally friendly lubricants, but also promote technological progress in related fields due to its advantages of simplicity, low production cost, excellent lubrication performance and anti-wear performance, and has broad market application prospects.

[0184] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A lubricant for drilling fluid, characterized in that: include: a) polyoctadecenoic acid ester; b) Fatty acid esters: products of transesterification of vegetable oils with polyethylene glycol.

2. A lubricant for drilling fluid according to claim 1, characterized in that: The mass ratio of polyoctadecenoic acid ester to fatty acid ester is (6-8):

1.

3. The lubricant for drilling fluid according to claim 1, characterized in that: The polyoctadecenoic acid ester is a product of condensation polymerization of octadecenoic acid and mixed fatty acids.

4. A lubricant for drilling fluid according to claim 3, characterized in that: The mixed fatty acid has a carbon chain length of 16 to 18, and preferably the mixed fatty acid is a mixture of hexadecanol and octadecyl alcohol, with a mixing mass ratio of 7:

3.

5. The lubricant for drilling fluid according to claim 3, characterized in that: The feed mass ratio of octadecenoic acid to mixed fatty acids is 1:(2.4-3.2).

6. The lubricant for drilling fluid according to claim 1, characterized in that: The vegetable oil is soybean oil, cottonseed oil, castor oil, etc., preferably soybean oil. The index of the vegetable oil is: solvent residue: ≤10 mg / kg.

7. The lubricant for drilling fluid according to claim 1, characterized in that: The grade of the polyethylene glycol is PEG-1000; the mass ratio of the vegetable oil to the polyethylene glycol is (5.8-8.4):

1.

8. A method for preparing a lubricant for drilling fluid according to any one of claims 1 to 7, characterized in that: include: S1, octadecenoic acid and mixed fatty alcohols undergo polycondensation reaction under the action of a catalyst to obtain polyoctadecenoic acid ester; S2, transesterification reaction of vegetable oil and polyethylene glycol to obtain fatty acid esters; S3, mixing the polyoctadecenoic acid ester of step S1 and the fatty acid ester of step S2 to obtain a lubricant for drilling fluid.

9. The method for preparing a lubricant for drilling fluid according to claim 8, characterized in that: In step S1, the catalyst is preferably sodium sulfate; the mass of sodium sulfate added is 1% to 3% of the mass of octadecenoic acid added, the reaction pressure is controlled to be -0.5MPa to -0.7MPa, the reaction temperature is controlled to be 150°C ± 5°C, and the reaction time is controlled to be at least 2h; In step S2, the reaction temperature is controlled at 120°C ± 5°C, and the reaction time is controlled at least 4 hours; In step S3, polyoctadecenoic acid ester and fatty acid ester are mixed by heating and stirring, the temperature is controlled at 85°C±5°C, and the stirring time is 1.5 hours.

10. A drilling fluid, characterized in that: A lubricant for drilling fluid comprising any one of claims 1 to 7.

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