Lignin-derived environmentally-friendly viscosity reducer for drilling fluid, and preparation method thereof

[0015] Example 1

[0016] In the first step, the lignin material is mixed with 2 times the mass water in a reaction vessel at room temperature, and the mixture is evenly stirred. The lignin material is industrial-grade sodium lignosulfonate, and the water is industrial-grade pure water;

[0017] In the second step, a metal salt with a mass ratio of 1:2 to the lignin material is added to the reaction vessel, and the mixture is stirred evenly, and the metal salt is industrial-grade ferric chloride;

[0018] The third step is to add 5% foam inhibitor of lignin material mass to the above-mentioned mixed liquid in the reaction vessel, and then add 3% formaldehyde of lignin material mass to it, stir evenly, and stir for 1 hour at 80°C. The foam inhibitor is an industrial grade cetylpyridinium chloride, and the formaldehyde is an industrial grade formaldehyde aqueous solution;

[0019] In the fourth step, the solvent of the above mixture is evaporated and pulverized to below 40 meshes to obtain a lignin-derived environment-friendly drilling fluid viscosity reducer.

[0020] Weigh 5mg of dry lignin-derived environment-friendly drilling fluid viscosity reducer with an analytical balance, place them in a miniature aluminum crucible, add the crucible lid and punch them to make samples to be tested, and place them in the sample holder of the DSC analyzer for analysis. With nitrogen protection, the temperature can be increased uniformly from 0 to 200°C within 20 minutes. The measured glass transition temperature is 163.6°C, which is higher than 156.0°C of the lignin raw material. The sample and KBr were mixed and ground into fine powder at 1:100 (mass ratio), placed in a tableting mold, pressed into a transparent sheet, placed on a sample holder for testing, and scanned at full wavelength (400-4000nm). At 3400cm -1 The wide and strong absorption peak nearby is O—H stretching vibration, 2895-2920cm -1 The absorption peak at is the stretching vibration of methyl and methylene C—H, 1595cm -1 And 1420cm -1 The absorption peak nearby is the vibration absorption of the benzene ring skeleton, which is 2895-2920cm compared with the lignin raw material -1 The absorption peak at is significantly enhanced, indicating that the increase in the number of alkyl groups in the component is enhanced.

[0021] Use GB/T16783.1-2014 "Oil and Natural Gas Industry Drilling Fluid Field Test Part 1: Water-based Drilling Fluid" to evaluate the viscosity of the drilling fluid, and use SY-T 5560-1992 "Defoamer Evaluation Procedure for Drilling Fluid" to evaluate the drilling fluid Foaming. When the amount of the viscosity reducer for the lignin-derived environmentally friendly drilling fluid is 0.3% of the drilling fluid, the viscosity of the water-based drilling fluid can be reduced by 31% at 30°C, and the drilling fluid does not foam during use.

[0022] Example 2

[0023] In the first step, the lignin material is mixed with 3 times the mass water in a reaction vessel at room temperature, and the mixture is evenly stirred. The lignin material is industrial grade calcium lignosulfonate, and the water is deionized water;

[0024] In the second step, a metal salt with a mass ratio of 1:3 to the lignin material is added to the above reaction vessel, and the mixture is stirred evenly, and the metal salt is chemically pure iron sulfate;

[0025] In the third step, add foam inhibitor with 3% mass of lignin material to the above-mentioned mixed liquid in the reaction vessel, and then add 2% formaldehyde with mass of lignin material to it, stir evenly, and stir for 2 hours at 60°C. The foam inhibitor is analytically pure dodecyltrimethylammonium chloride, and the formaldehyde is a chemically pure aqueous formaldehyde solution;

[0026] In the fourth step, the solvent of the above mixture is evaporated and pulverized to below 40 meshes to obtain a lignin-derived environment-friendly drilling fluid viscosity reducer.

[0027] Weigh 5mg of dry lignin-derived environment-friendly drilling fluid viscosity reducer with an analytical balance, place them in a miniature aluminum crucible, add the crucible lid and punch them to make samples to be tested, and place them in the sample holder of the DSC analyzer for analysis. With nitrogen protection, the temperature can be increased uniformly from 0 to 200°C within 20 minutes. The measured glass transition temperature is 163.3°C, which is higher than 157.0°C of the lignin raw material. The sample and KBr were mixed and ground into fine powder at 1:100 (mass ratio), placed in a tableting mold, pressed into a transparent sheet, placed on a sample holder for testing, and scanned at full wavelength (400-4000nm). At 3400cm -1 The wide and strong absorption peak nearby is O—H stretching vibration, 2895-2920cm -1 The absorption peak at is the stretching vibration of methyl and methylene C—H, 1595cm -1 And 1420cm -1 The absorption peak nearby is the vibration absorption of the benzene ring skeleton, which is 2896-2920cm compared with the lignin raw material -1 The absorption peak at is significantly enhanced, indicating that the increase in the number of alkyl groups in the component is enhanced.

[0028] Use GB/T16783.1-2014 "Oil and Natural Gas Industry Drilling Fluid Field Test Part 1: Water-based Drilling Fluid" to evaluate the viscosity of the drilling fluid, and use SY-T 5560-1992 "Defoamer Evaluation Procedure for Drilling Fluid" to evaluate the drilling fluid Foaming. When the amount of the viscosity reducer for the lignin-derived environmentally friendly drilling fluid is 0.5% of the drilling fluid, the viscosity of the water-based drilling fluid can be reduced by 39% at 60°C, and the drilling fluid does not foam during use.

[0029] Example 3

[0030] In the first step, the lignin material is mixed with 5 times the mass water in a reaction vessel at room temperature, and the mixture is evenly stirred. The lignin material is chemically soda lignin, and the water is industrial-grade mineral water;

[0031] In the second step, a metal salt with a mass ratio of 1:5 to the lignin material is added to the reaction vessel, and the mixture is stirred evenly, and the metal salt is chemically pure ferrous chloride;

[0032] In the third step, add 2% foam inhibitor of lignin material mass to the above-mentioned mixed liquid in the reaction vessel, and then add 1% formaldehyde of lignin material mass to it, stir evenly, and stir for 4 hours at 65°C. The foam inhibitor is analytically pure cetyltrimethylammonium chloride, and the formaldehyde is analytically pure trioxane;

[0033] In the fourth step, the solvent of the above mixture is evaporated and crushed to below 40 meshes to obtain a lignin-derived environment-friendly drilling fluid viscosity reducer.

[0034] Weigh 5mg of dry lignin-derived environment-friendly drilling fluid viscosity reducer with an analytical balance, place them in a miniature aluminum crucible, add the crucible lid and punch them to make samples to be tested, and place them in the sample holder of the DSC analyzer for analysis. With nitrogen protection, the temperature can be uniformly increased from 0 to 200°C within 20 minutes. The measured glass transition temperature is 164.5°C, which is higher than 155.0°C of the lignin raw material. The sample and KBr were mixed and ground into fine powder according to 1:100 (mass ratio), placed in a tableting mold, pressed into a transparent sheet, placed on a sample holder for testing, and performed full-wavelength scanning (400-4000nm). At 3400cm -1 The wide and strong absorption peak nearby is O—H stretching vibration, 2895-2920cm -1 The absorption peak at is the stretching vibration of methyl and methylene C—H, 1595cm -1 And 1420cm -1 The absorption peak nearby is the vibration absorption of the benzene ring skeleton, which is 2895-2920cm compared with the lignin raw material -1 The absorption peak at is significantly enhanced, indicating that the increase in the number of alkyl groups in the component is enhanced.

[0035] Use GB/T16783.1-2014 "Oil and Natural Gas Industry Drilling Fluid Field Test Part 1: Water-based Drilling Fluid" to evaluate the viscosity of the drilling fluid, and use SY-T 5560-1992 "Defoamer Evaluation Procedure for Drilling Fluid" to evaluate the drilling fluid Foaming. When the amount of the viscosity reducer for the lignin-derived environmentally friendly drilling fluid is 1% of the drilling fluid, the viscosity of the water-based drilling fluid can be reduced by 42% at 90°C, and the drilling fluid does not foam during use.