Preparation method and application of high-temperature-resistant biomass-based fluid loss additive for drilling fluid

Abstract

The application relates to a preparation method and application of a high-temperature-resistant biomass-based fluid loss additive for a drilling fluid. In the method, monosaccharide is added into deionized water, TEMPO oxidized cellulose nanomaterial is added after being dissolved, a high-temperature-resistant monomer is doped into the suspension, is uniformly mixed, is heated to react, is cooled, is centrifuged, is washed, and is dried to obtain the high-temperature-resistant biomass-based fluid loss additive. In the application, a high-temperature-resistant carbon shell is generated on the surface of cellulose nanomaterial through hydrothermal carbonization reaction of glucose under subcritical water conditions, and a high-temperature-resistant sulfonic acid group is grafted on the surface of the carbon shell in situ through addition of a high-temperature-resistant monomer containing a sulfonic acid group, so that the surface carbonized and modified cellulose nanomaterial fluid loss additive is obtained. The high-temperature-resistant biomass-based fluid loss additive has excellent high-temperature aging resistance, still has excellent barite suspension capacity after 16h of rolling aging at 240 DEG C, and can meet the application requirements of deep drilling fluid fluid loss.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying a high-temperature resistant biomass-based cutting agent for drilling fluids, belonging to the field of drilling fluid technology for oil and gas field exploration and development. Background Technology

[0002] With the continuous advancement of drilling technology, the requirements for drilling fluids are becoming increasingly stringent. Especially in the development of ultra-deep and extra-deep unconventional oil and gas resources, drilling fluids need to remain stable under extremely high temperatures and pressures. Barite, a high-density mineral, is often used to weight drilling fluids to increase their density, thereby maintaining pressure balance within the wellbore in high-pressure oil and gas formations. However, in traditional drilling fluids, barite, due to its high density, is prone to settling, leading to uneven drilling fluid density and affecting the performance of the drilling fluid and the safety of the drilling process. To address this issue, various chemical additives are typically added to improve the suspension stability of barite. Although many chemical additives for suspending barite exist on the market, their effectiveness is often limited in the high-temperature and high-pressure drilling environment. High temperatures accelerate the decomposition of chemical additives, reducing their stabilizing effect, and also cause changes in drilling fluid viscosity, further exacerbating barite settling. Therefore, developing materials and technologies that can effectively improve the suspension stability of barite under high-temperature and high-pressure conditions is of great significance for improving the efficiency and safety of deep drilling.

[0003] Patent document CN117903763A discloses a method for preparing a cutting agent by reacting a polybasic acid and a polyamine. The prepared cutting agent for oil-based drilling fluid exhibits good temperature resistance and cutting effect, significantly improving the rheological properties and suspension stability of oil-based drilling fluids under high-temperature conditions. It also has low viscosity, eliminating the need for diluents and effectively solving problems such as barite settling and poor rock-carrying capacity in high-temperature, high-density oil-based drilling fluids. However, the hot rolling temperature of this cutting agent is 160℃, and the settling index was not tested. Patent document CN116103020A discloses a method for improving temperature resistance by introducing a polybasic acid containing a benzene ring structure into the molecule. Patent document CN113943422A discloses a method for preparing a flow modifier through a combined reaction of polyaniline and its derivatives, polyol amines, piperazine derivatives, and fatty acids. Both methods can significantly improve the rheological properties of oil-based drilling fluids under high-temperature conditions, reduce the amount of organic soil used, and increase the tolerance for low-density solid phases, solving the problems of barite settling and rock-carrying capacity in horizontal wells and high-temperature deep well drilling. However, in the preparation of the cutting agent, both methods use a large amount of petroleum-based chemicals, which has a significant impact on the formation and does not meet the requirements of green environmental protection; in addition, the high cost of the raw materials used is not conducive to large-scale application.

[0004] Therefore, it is of great significance to develop a green, environmentally friendly, and low-cost high-temperature resistant biomass-based extractant. Summary of the Invention

[0005] In view of the shortcomings of existing technologies, especially the problems of poor suspension stability of barite in drilling fluids and formation pollution in high-temperature and high-pressure formations, this invention provides a method for preparing and applying a high-temperature resistant biomass-based cutting agent for drilling fluids.

[0006] The high-temperature resistant biomass-based cutting agent prepared by this invention, when added to drilling fluid, can maintain the high-temperature suspension stability of barite in drilling fluid, and can also stabilize barite without harming the environment, thus meeting the requirements of green environmental protection.

[0007] This invention is achieved through the following technical solution:

[0008] A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids includes the following steps:

[0009] 1) Add monosaccharides to deionized water, stir to dissolve, then add TEMPO oxidized cellulose nanomaterials, stir evenly to obtain a suspension;

[0010] 2) The high-temperature resistant monomer is incorporated into the suspension and mixed evenly. The homogeneous suspension is heated and stirred. After the reaction, the suspension is cooled to ambient temperature, centrifuged, washed with anhydrous ethanol and deionized water, and dried to obtain the high-temperature resistant biomass-based extractant.

[0011] According to a preferred embodiment of the present invention, the TEMPO oxidized cellulose nanomaterial is prepared by the following method:

[0012] (1) Take 5g of biomass raw material and pour it into 250mL of acidic NaClO2 solution with a mass fraction of 2.5wt%. After stirring thoroughly, heat it in a water bath at 75℃ for 1h. Filter it under vacuum. Repeat this process 6-8 times. Wash the product obtained from the reaction with deionized water until neutral and then dry it. Pour the dried product into 250mL of NaOH solution with a mass fraction of 5wt%. Stir it continuously at 80℃ for 2h. After filtration, wash it with distilled water until neutral and then put it in an oven to dry for 24h to obtain cellulose.

[0013] (2) Add 0.016g TEMPO and 0.1g sodium bromide to 100mL of deionized water. After they are completely dissolved, add 1g cellulose and stir well. Add NaClO to the system. At the beginning of the reaction, adjust the pH of the solution to 10 by adding 0.5mol / L HCl. As the reaction time increases, the pH of the solution decreases. Then slowly add 0.5wt% NaOH to maintain the pH of the reaction system at 10. When the pH is constant, immediately add ethanol to terminate the reaction and wash thoroughly until the conductivity of the reaction solution is the same as that of water to obtain TEMPO oxidized cellulose.

[0014] (3) TEMPO oxidized cellulose was prepared into a slurry with a concentration of 2 mg / mL using deionized water, and then sonicated in an ice-water bath and centrifuged to obtain TEMPO oxidized cellulose nanomaterials.

[0015] According to a preferred embodiment of the present invention, in step (1), the biomass raw material is straw powder, pulp or bamboo powder, and most preferably, the biomass raw material is straw powder.

[0016] According to a preferred embodiment of the present invention, in step (2), the concentration of NaClO is 10 mmol / g.

[0017] According to a preferred embodiment of the present invention, in step (2), the entire TEMPO oxidation reaction is carried out in an ultrasonic cleaner at an ultrasonic frequency of 45 kHz.

[0018] According to a preferred embodiment of the present invention, in step (3), the ultrasound is performed at a power of 500W for 20 minutes, and the centrifugation is performed at 10000r / min for 8 minutes.

[0019] According to a preferred embodiment of the present invention, in step 1), the monosaccharide is glucose, fructose, ribose, or deoxyribose.

[0020] Most preferably, in step 1), the monosaccharide is glucose.

[0021] According to a preferred embodiment of the present invention, in step 1), the mass-to-volume ratio of monosaccharide to deionized water is (10-30):(300-600), unit: g / mL.

[0022] According to a preferred embodiment of the present invention, in step 1), the stirring and dissolving process is carried out by stirring at a speed of 8000-12000 rpm for 20-40 minutes.

[0023] According to a preferred embodiment of the present invention, in step 1), the mass ratio of monosaccharide to TEMPO oxidized cellulose nanomaterial is (1.5-3.5):(0.3-0.7).

[0024] According to a preferred embodiment of the present invention, in step 1), after adding TEMPO oxidized cellulose nanomaterials, the mixture is stirred at a speed of 8000-12000 rpm for 20-40 minutes.

[0025] According to a preferred embodiment of the present invention, in step 2), the high-temperature resistant monomer is sodium α-olefin sulfonate, sodium styrene sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, or sodium acryloyldimethyl taurate.

[0026] Most preferably, in step 2), the high-temperature resistant monomer is sodium styrene sulfonate.

[0027] According to a preferred embodiment of the present invention, in step 2), the mass ratio of the high-temperature resistant monomer to the TEMPO oxidized cellulose nanomaterial is (4.5-7):(0.4-1.2).

[0028] According to a preferred embodiment of the present invention, in step 2), heating and stirring involves placing the uniformly mixed homogeneous suspension in a high-pressure reactor lined with polytetrafluoroethylene and stirring it in a rolling oven at 160-190°C for 3-6 hours.

[0029] According to a preferred embodiment of the present invention, in step 2), the centrifugation speed is 8000-12000 rpm and the centrifugation time is 5-15 min.

[0030] According to a preferred embodiment of the present invention, in step 2), the drying process involves placing the washed and separated precipitate in an oven at a temperature of 75-85°C for 24 hours.

[0031] This invention significantly improves the high-temperature suspension stability of barite in drilling fluids through surface carbonization and chemical modification of cellulose nanomaterials. This method not only maintains the uniform suspension of barite in drilling fluids but also reduces reliance on petroleum-based chemical additives, enhancing the performance stability and environmental characteristics of drilling fluids. It has significant practical implications for solving the problem of barite sedimentation in drilling fluids.

[0032] A high-temperature resistant biomass-based cutting agent for drilling fluid is prepared using the above method.

[0033] The above-mentioned high-temperature resistant biomass-based cutting agent for drilling fluids is applied to drilling fluids to maintain the high-temperature suspension stability of barite in drilling fluids.

[0034] The technical features and beneficial effects of this invention are as follows:

[0035] 1. This invention uses cellulose nanomaterials as raw materials, and modifies them through hydrothermal carbonization and sulfonation with monosaccharides to obtain a slicing agent with excellent high-temperature resistance and barite suspension properties. Compared with traditional high-temperature sedimentation inhibitors, the cellulose nanomaterials used in this invention have the characteristics of wide availability of raw materials, easy biodegradability, renewability, and non-toxicity, which is beneficial to the construction of green oilfields in my country.

[0036] 2. This invention generates a high-temperature resistant carbon shell on the surface of cellulose nanomaterials by hydrothermal carbonization of glucose under subcritical water conditions, and further obtains a surface carbonization and modified cellulose nanomaterial slicing agent by adding a high-temperature resistant monomer containing sulfonate groups to graft high-temperature resistant sulfonate functional groups on the surface of the carbon shell.

[0037] 3. The cutting agent of the present invention has excellent resistance to high temperature aging. After rolling aging at 240°C for 16 hours, it still has excellent barite suspension ability, which can meet the application requirements of deep drilling fluid cutting. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The raw materials used in the embodiments are all conventional raw materials that can be obtained commercially; the methods described are all prior art unless otherwise specified. Based on the embodiments of the present invention, all other examples that are improved or modified by those skilled in the art are within the scope of protection of the present invention.

[0039] Example 1

[0040] Preparation method of TEMPO oxidized cellulose nanomaterials:

[0041] 5g of straw powder was poured into 250mL of a 2.5wt% acidic NaClO2 solution, stirred thoroughly, and heated in a 75℃ water bath for 1 hour. The mixture was then vacuum filtered, and this process was repeated 6 times. The product was washed with deionized water until neutral and then dried. The dried product was poured into 250mL of a 5wt% NaOH solution and stirred continuously at 80℃ for 2 hours. After filtration, it was washed with distilled water until neutral and then dried in an oven for 24 hours to obtain cellulose. 0.016g of TEMPO and 0.1g of sodium bromide were added to 100mL of deionized water. After complete dissolution, 1g of cellulose was added and stirred thoroughly. 10mmol / g NaClO was added to the TEMPO oxidation system. Initially, the pH of the solution was adjusted to 10 by adding 0.5mol / L HCl dropwise. As the reaction time increased, the pH of the solution decreased. Then, 0.5 wt% NaOH was slowly added dropwise to maintain the pH of the reaction system at around 10. When the pH remained constant, ethanol solution was immediately added to terminate the reaction, and the solution was thoroughly washed until the conductivity of the reaction solution was similar to that of water. The entire TEMPO oxidation reaction was carried out in an ultrasonic cleaner at a frequency of 45 kHz. The oxidized cellulose was prepared into a 2 mg / mL slurry using deionized water, then sonicated at 500 W for 20 min in an ice-water bath, and finally centrifuged at 10000 r / min for 8 min to obtain TEMPO oxidized cellulose nanomaterials with an average diameter of 4 nm.

[0042] The preparation method of high-temperature resistant biomass-based cutting agent for drilling fluids includes the following steps:

[0043] Dissolve 20g of glucose in 400mL of deionized water and stir at 10000rpm for 30 minutes. Then add 5g of TEMPO oxidized cellulose nanomaterial and stir at 10000rpm for 30 minutes to incorporate it into the suspension. Finally, add sodium styrene sulfonate. The mass ratio of sodium styrene sulfonate to TEMPO oxidized cellulose nanomaterial is 5:0.6.

[0044] The final homogeneous suspension was placed in a polytetrafluoroethylene-lined autoclave and stirred in a 180°C rotating oven for 4 hours. After the reaction, the suspension was cooled to ambient temperature, centrifuged at 10,000 rpm for 10 minutes, and washed several times with anhydrous ethanol and deionized water. The separated dark brown precipitate was dried at 80°C for 24 hours to obtain heat-resistant biomass-based extractant A1.

[0045] Comparative Example 1

[0046] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0047] In the preparation of the cutting agent, only glucose is added without sodium styrene sulfonate to obtain high-temperature resistant biomass-based cutting agent A2.

[0048] Comparative Example 2

[0049] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0050] In the preparation of the cutting agent, only sodium styrene sulfonate was added without glucose to obtain a high-temperature resistant biomass-based cutting agent A3.

[0051] Comparative Example 3

[0052] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0053] In the preparation of TEMPO oxidized cellulose nanomaterials, the concentration of NaClO was changed to 4 mmol / g to obtain cellulose nanomaterials with an average diameter of 20 nm. Other steps were carried out as in Example 1 to obtain high-temperature resistant biomass-based extractant A4.

[0054] Comparative Example 4

[0055] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0056] In the preparation of TEMPO oxidized cellulose nanomaterials, the concentration of NaClO was changed to 6 mmol / g to obtain cellulose nanomaterials with an average diameter of 10 nm. Other steps were carried out as in Example 1 to obtain high-temperature resistant biomass-based extractant A5.

[0057] Comparative Example 5

[0058] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0059] When preparing cellulose nanomaterials by TEMPO oxidation, the concentration of NaClO was changed to 8 mmol / g to obtain cellulose nanomaterials with an average size of 8 nm. Other steps were carried out as in Example 1 to obtain high-temperature resistant biomass-based extractant A6.

[0060] Comparative Example 6

[0061] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0062] In the preparation of the cutting agent, fructose was used instead of glucose to obtain heat-resistant biomass-based cutting agent A7.

[0063] Comparative Example 7

[0064] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0065] In the preparation of the cutting agent, deoxyribose was used instead of glucose to obtain a high-temperature resistant biomass-based cutting agent A8.

[0066] Comparative Example 8

[0067] A method for preparing a novel drilling fluid lifting agent is described in Example 1, except that:

[0068] In the preparation of the cutting agent, sodium α-olefin sulfonate was used instead of sodium styrene sulfonate to obtain high-temperature resistant biomass-based cutting agent A9.

[0069] Comparative Example 9

[0070] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0071] In the preparation of the cutting agent, 2-acrylamido-2-methylpropanesulfonic acid was used instead of sodium styrene sulfonate to obtain high-temperature resistant biomass-based cutting agent A10.

[0072] Comparative Example 10

[0073] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0074] In the preparation of the cutting agent, sodium acryloyl dimethyl taurate was used instead of sodium styrene sulfonate to obtain high-temperature resistant biomass-based cutting agent A11.

[0075] Comparative Example 11

[0076] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0077] In the preparation of the cutting agent, the mass ratio of glucose to cellulose nanomaterials prepared by TEMPO oxidation was 8:1, resulting in a high-temperature resistant biomass-based cutting agent A12.

[0078] Comparative Example 12

[0079] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0080] In the preparation of the cutting agent, the mass ratio of glucose to TEMPO oxidized cellulose nanomaterials was 1:1, resulting in a high-temperature resistant biomass-based cutting agent A13.

[0081] Comparative Example 13

[0082] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0083] In the preparation of the cutting agent, the mass ratio of sodium styrene sulfonate to TEMPO oxidized cellulose nanomaterials was 9:1, resulting in high-temperature resistant biomass-based cutting agent A14.

[0084] Comparative Example 14

[0085] A method for preparing a cutting agent for drilling fluid is described in Example 1, except that:

[0086] In the preparation of the cutting agent, the mass ratio of sodium styrene sulfonate to TEMPO oxidized cellulose nanomaterials is 2:1, resulting in high-temperature resistant biomass-based cutting agent A15.

[0087] Performance testing

[0088] The cutting agents prepared in the experimental and comparative examples were added to the drilling fluid for performance evaluation.

[0089] Drilling fluid formulation: 320mL diesel oil + 80mL 25wt% CaCl2 solution + 28g emulsifier + 12g organic clay + 10g oxidized asphalt + 8g CaO, finally weighted to 1.6g / cm³ with barite. 3 One sample was taken as a blank sample, and 2g of surface carbonized and modified cellulose nanomaterials were added to the other 10 samples respectively. The samples were rolled and aged at 240℃ for 16h, and the performance was tested. The test results are shown in Table 1.

[0090] Table 1. Effects of cutting agent on drilling fluid

[0091] 1 Drilling fluid 240℃ / 16h 37.5 31 6.1 0.562 2 Drilling fluid + A1 240℃ / 16h 52 35 17 0.506 3 Drilling fluid + A2 240℃ / 16h 42 31.5 10.5 0.522 4 Drilling fluid + A3 240℃ / 16h 44.5 32.5 12 0.518 5 Drilling fluid + A4 240℃ / 16h 46 33.5 12.5 0.532 6 Drilling fluid + A5 240℃ / 16h 48 32 16 0.524 7 Drilling fluid + A6 240℃ / 16h 47 32.5 15.5 0.516 8 Drilling fluid + A7 240℃ / 16h 48 33 15 0.512 9 Drilling fluid + A8 240℃ / 16h 48.5 32 16.5 0.522 10 Drilling fluid + A9 240℃ / 16h 47.5 31.5 16 0.524 11 Drilling fluid + A10 240℃ / 16h 46 32 14 0.526 12 Drilling fluid + A11 240℃ / 16h 48 33 15 0.525 13 Drilling fluid + A12 240℃ / 16h 50 36 14 0.525 14 Drilling fluid + A13 240℃ / 16h 40 32 10 0.523 15 Drilling fluid + A14 240℃ / 16h 48 34 14 0.516 16 Drilling fluid + A15 240℃ / 16h 46.5 34 12.5 0.532

[0092] As shown in Table 1, Example 1 exhibits excellent high-temperature suspension stability of barite under high-temperature conditions, meeting the requirements for maintaining the high-temperature stability of barite in drilling fluids within high-temperature formations. This is because glucose undergoes a hydrothermal carbonization reaction at high temperatures, generating a high-temperature resistant carbon shell on the surface of the cellulose nanomaterials. Furthermore, sodium styrene sulfonate grafts sulfonate groups onto the surface-carbonized cellulose nanomaterials at high temperatures, further enhancing the temperature resistance of the cellulose nanomaterials. The surface-carbonized and sulfonated modified cellulose nanomaterials form a dense network that effectively suspends barite, thereby improving its suspension performance. Compared to sample 2, sample 3 lacks the addition of glucose, while sample 4 does not contain sodium styrene sulfonate. The resulting shaving agents, one lacking a carbon shell and the other not undergoing sulfonation modification, exhibit poorer barite suspension performance compared to sample 2. Samples 5, 6, and 7, compared to sample 2, altered the concentration of NaClO in the TEMPO oxidation process for preparing cellulose nanomaterials, thus changing the average diameter of the prepared cellulose nanomaterials. Studies have found that as the NaClO concentration decreases, the diameter of cellulose nanomaterials gradually increases, which is not conducive to the formation of a dense network structure, thus reducing the suspending ability of barite. Compared to sample 2, samples 8 and 9 altered the types of monosaccharides used in the hydrothermal reaction. Glucose, compared to deoxyribose, has more carbon atoms and the ability to form ring structures, making it easier to form stable carbon materials. Compared to fructose, glucose has an aldehyde group, making the intermediates more prone to polymerization and condensation reactions, and forming a stable carbon skeleton structure is relatively easier through dehydration and polymerization reactions to form stable carbon materials. Compared to sample 2, samples 10, 11, and 12 altered the high-temperature resistant monomers in the modification of cellulose nanomaterials. Sodium styrene sulfonate, compared to sodium α-olefin sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, and sodium acryloyldimethyl taurate, has a molecular structure that simultaneously contains high-temperature resistant and chemically stable sulfonic acid groups and benzene rings, endowing surface carbonization and modified cellulose nanomaterials with excellent high-temperature resistance. Compared to sample 2, samples 13 and 14 showed an altered mass ratio of glucose to cellulose nanomaterials prepared by TEMPO oxidation. An excessively high glucose mass ratio easily leads to large-molecule sedimentation, while an excessively low ratio results in uneven distribution of the carbon shell attached to the cellulose nanomaterials, thus affecting performance. Similarly, samples 15 and 16, compared to sample 2, showed an altered mass ratio of sodium styrene sulfonate to cellulose nanomaterials prepared by TEMPO oxidation. An excessively high sodium styrene sulfonate content leads to over-dispersion of the cellulose nanomaterials, reducing their mechanical strength and structural stability, and also lowers their thermal stability. An excessively low sodium styrene sulfonate content fails to effectively modify the cellulose nanomaterials, and insufficient modification results in agglomeration, further affecting performance. In conclusion, the drilling fluid lifting agent of this invention can be used in high-temperature, high-pressure, and ultra-deep well drilling processes.

[0093] Example 2

[0094] A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids, following Example 1, with the difference being:

[0095] The amount of glucose used was 30g, and the rest was carried out as in Example 1.

[0096] Example 3

[0097] A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids, following Example 1, with the difference being:

[0098] The amount of TEMPO oxidized cellulose nanomaterial used was 6g, and other procedures were carried out as in Example 1.

[0099] Example 4

[0100] A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids, following Example 1, with the difference being:

[0101] The mass ratio of sodium styrene sulfonate to TEMPO oxidized cellulose nanomaterials was 5:0.7, and other procedures were carried out as in Example 1.

[0102] Example 5

[0103] A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids, following Example 1, with the difference being:

[0104] The mass ratio of sodium styrene sulfonate to TEMPO oxidized cellulose nanomaterials was 5:0.8, and other procedures were carried out as in Example 1.

[0105] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-temperature resistant biomass-based cutting agent for drilling fluids, comprising the following steps: 1) Add monosaccharides to deionized water, stir to dissolve, then add TEMPO oxidized cellulose nanomaterials, stir evenly to obtain a suspension; 2) The high-temperature resistant monomer is incorporated into the suspension and mixed evenly. The homogeneous suspension is heated and stirred. After the reaction, the suspension is cooled to ambient temperature, centrifuged, washed with anhydrous ethanol and deionized water, and dried to obtain the high-temperature resistant biomass-based extractant. The high-temperature resistant monomer is sodium styrene sulfonate, and the mass ratio of the high-temperature resistant monomer to TEMPO oxidized cellulose nanomaterials is (4.5-7):(0.4-1.2). Heating and stirring are carried out by placing the homogeneous suspension in a high-pressure autoclave lined with polytetrafluoroethylene and stirring it in a rolling oven at 160-190℃ for 3-6 hours. The centrifugation speed is 8000-12000 rpm and the centrifugation time is 5-15 min. The drying is carried out by placing the washed and separated precipitate in an oven at 75-85℃ for 24 hours.

2. The preparation method according to claim 1, characterized in that, TEMPO oxidized cellulose nanomaterials were prepared by the following method: (1) Take 5g of biomass raw material and pour it into 250mL of acidic NaClO2 solution with a mass fraction of 2.5wt%. After stirring thoroughly, heat it in a water bath at 75℃ for 1h. Filter it under vacuum. Repeat this process 6-8 times. Wash the product obtained from the reaction with deionized water until neutral and then dry it. Pour the dried product into 250mL of NaOH solution with a mass fraction of 5wt%. Stir it continuously at 80℃ for 2h. After filtration, wash it with distilled water until neutral and then put it in an oven to dry for 24h to obtain cellulose. (2) Add 0.016g TEMPO and 0.1g sodium bromide to 100mL of deionized water. After they are completely dissolved, add 1g cellulose and stir well. Add NaClO to the system. At the beginning of the reaction, adjust the pH of the solution to 10 by adding 0.5mol / L HCl. As the reaction time increases, the pH of the solution decreases. Then slowly add 0.5wt% NaOH to maintain the pH of the reaction system at 10. When the pH is constant, immediately add ethanol to terminate the reaction and wash thoroughly until the conductivity of the reaction solution is the same as that of water to obtain TEMPO oxidized cellulose. (3) TEMPO oxidized cellulose was prepared into a slurry with a concentration of 2 mg / mL using deionized water, and then sonicated in an ice-water bath and centrifuged to obtain TEMPO oxidized cellulose nanomaterials.

3. The preparation method according to claim 2, characterized in that, In step (1), the biomass raw material is straw powder, pulp or bamboo powder. In step (2), the concentration of NaClO is 10 mmol / g. The entire TEMPO oxidation reaction is carried out in an ultrasonic cleaner with an ultrasonic frequency of 45 kHz. In step (3), the ultrasonic treatment is performed at 500W power for 20 min, and the centrifugation is performed at 10000 r / min for 8 min.

4. The preparation method according to claim 1, characterized in that, In step 1), the monosaccharide is glucose, fructose, ribose or deoxyribose; in step 1), the mass-to-volume ratio of the monosaccharide to deionized water is (10-30):(300-600), unit, g / mL.

5. The preparation method according to claim 1, characterized in that, In step 1), the stirring and dissolving process involves stirring at 8000-12000 rpm for 20-40 minutes. In step 1), the mass ratio of monosaccharide to TEMPO oxidized cellulose nanomaterial is (1.5-3.5):(0.3-0.7). In step 1), after adding TEMPO oxidized cellulose nanomaterial, the mixture is stirred at 8000-12000 rpm for 20-40 minutes.

6. A high-temperature resistant biomass-based cutting agent for drilling fluid, prepared by the method described in any one of claims 1-5.

7. The application of the high-temperature resistant biomass-based cutting agent for drilling fluid as described in claim 6, applied to drilling fluid, to maintain the high-temperature suspension stability of barite in drilling fluid.