Oil-gas lubrication and resistance reduction type water-based drilling fluid for ground with depth of 10,000 meters as well as preparation method and application thereof

Abstract

The invention provides a myriameter deep ground oil-gas lubrication resistance-reducing water-based drilling fluid as well as a preparation method and application thereof, and belongs to the technical field of drilling fluids. The oil-gas lubrication resistance-reducing type water-based drilling fluid for the 10000-meter deep ground comprises the following raw materials in parts by weight: 100 parts of water, 5-10 parts of light diesel oil, 1-4 parts of high-temperature-resistant clay, 3-6 parts of a dendritic macromolecular filtrate reducer, 2-4 parts of a temperature response micelle shear strength improving agent, 2-4 parts of a high-temperature-resistant strong-adsorption blocking agent, 3-5 parts of a nano composite polymer brush lubricant and 1-3 parts of a high-temperature-resistant system stabilizer. According to the invention, the filtrate reducer, the shear strength improving agent, the plugging agent, the lubricant and other components cooperate with each other to achieve synergistic interaction, so that the drilling fluid has low viscosity and good lubricating property and sedimentation stability under the conditions of 240 DEG C, saturated salt and high density, and can increase the mechanical drilling speed, slow down the wear of a drill bit, reduce drilling accidents such as differential pressure jamming and the like; and the drilling time and the total cost of a myriameter-deep oil-gas well are reduced.

Description

Technical Field

[0001] The invention relates to a 10,000-meter deep underground oil and gas lubrication and drag-reducing water-based drilling fluid and a preparation method and application thereof, belonging to the technical field of drilling fluids. Background Art

[0002] The geological conditions in ultra-deep layers are complex, with ultra-high temperatures (>220°C), ultra-high salt (>15%), and ultra-high pressure (>140MPa). The formation fluids, lithology, and pressure systems are complex, which can easily lead to underground accidents such as well wall collapse and block drop, drill jamming, overflow, and leakage, which brings huge challenges to safe and efficient drilling. Drilling fluid is a working fluid that meets the needs of drilling engineering. It is called the "blood" of drilling. It has the functions of stabilizing the well wall, carrying cuttings, balancing formation pressure, and transmitting water power. It is an indispensable core engineering technology for oil and gas exploration and development. However, in ultra-deep layers with high temperatures, high salts, and high pressures, the existing drilling fluids generally have poor stability and difficult to control performance. In order to balance the formation pressure, deep-layer high-temperature and high-salt salt-based drilling fluids generally have a higher density. Due to the high solid content, ultra-high-density drilling fluids have problems such as excessive viscosity, increased filtration loss, and poor lubrication performance, which bring difficulties to drilling construction and are difficult to meet the needs of oil and gas drilling at a depth of 10,000 meters.

[0003] Most of the existing research on ultra-deep and even 10,000-meter deep drilling fluids only focuses on the temperature and salt resistance of drilling fluids. For example, Chinese patent documents CN117736707A and CN115466603A respectively disclose a 230°C high-salt-resistant high-density water-based drilling fluid and its preparation method and application, and a 240°C salt-resistant plugging water-based drilling fluid and its preparation method and application. These drilling fluids show good rheological and filtration properties at 230°C and higher temperatures and high-salt conditions. However, in actual applications, due to the need to balance the formation pressure, the drilling fluid needs to be increased to a higher density. Excessive viscosity of the drilling fluid will lead to slower drilling speed, increased friction, drilling fluid sedimentation and stratification, and frequent adhesion and drilling, which seriously increases the drilling cost and drilling risk of 10,000-meter deep oil and gas wells.

[0004] Therefore, it is urgent to develop a water-based drilling fluid that has low viscosity, good lubrication performance and sedimentation stability under 240°C, saturated salt and high density conditions, so as to increase the mechanical drilling speed, reduce drill bit wear, and reduce drilling accidents such as differential pressure sticking. For this reason, the present invention is proposed. Summary of the invention

[0005] In view of the deficiencies of the prior art, especially the problems of excessive viscosity, difficult rheological properties, excessive friction, serious wear and tear of drill tools, high cost, easy sedimentation, and unstable density of drilling fluid under high-density conditions of water-based drilling fluid in deep formations, the present invention provides a 10,000-meter deep oil and gas lubricating and drag-reducing water-based drilling fluid and its preparation method and application. The present invention uses high-temperature resistant clay, dendritic macromolecular filtrate reducer, temperature-responsive micelle shearing agent, high-temperature resistant strong adsorption plugging agent, nanocomposite polymer brush lubricant, and high-temperature resistant system stabilizer as core components to construct a 10,000-meter deep oil and gas lubricating and drag-reducing water-based drilling fluid. The drilling fluid can have low viscosity, good lubrication properties and sedimentation stability under 240°C, saturated salt, and high-density conditions, can increase mechanical drilling speed, slow down drill bit wear, reduce drilling accidents such as differential pressure stuck drilling, and reduce the drilling time and overall cost of 10,000-meter deep oil and gas wells.

[0006] The present invention is achieved through the following technical solutions: A 10,000-meter deep underground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 5-10 parts of light diesel, 1-4 parts of high-temperature resistant clay, 3-6 parts of dendritic macromolecular filtrate reducer, 2-4 parts of temperature-responsive micelle shearing agent, 2-4 parts of high-temperature resistant strong adsorption plugging agent, 3-5 parts of nano-composite polymer brush lubricant, and 1-3 parts of high-temperature resistant system stabilizer.

[0007] Preferably according to the present invention, the light diesel is one or a combination of two or more of 0#, -10#, -20# and -35# diesel, which are common commercial products.

[0008] Preferably according to the present invention, the high temperature resistant clay is obtained by using the raw materials and preparation method in Chinese patent document CN118374267A.

[0009] Preferably, according to the present invention, the dendritic macromolecular fluid loss reducer is prepared according to the following method: (1) Place the methanol solution of ethylenediamine in an ice water bath and cool to 0-2°C under nitrogen protection; (2) adding a methanol solution of methyl methacrylate to a methanol solution of ethylenediamine, allowing the mixture to stand for a reaction; after the reaction is completed, removing methanol and excess methyl methacrylate to obtain a dendritic monomer; (3) adding N,N-diethylacrylamide, methacryloylethyl sulfobetaine, lauryl hydroxysulfobetaine and sodium p-styrene sulfonate into deionized water, and then adding a dendritic monomer under ultrasonic conditions to obtain a monomer solution; (4) The monomer solution is heated to a first reaction temperature under nitrogen protection, and ammonium cerium nitrate is added to carry out a first reaction; then the temperature is raised to a second reaction temperature, and 2,2'-azobisisobutylamidine dihydrochloride is added to carry out a second reaction; after the reaction is completed, the dendrimer macromolecular fluid loss reducer is obtained through dialysis and freeze drying.

[0010] Preferably, the mass ratio of ethylenediamine to methanol in the methanol solution of ethylenediamine in step (1) is 1:4-6.

[0011] Preferably, in the methanol solution of methyl methacrylate in step (2), the mass ratio of methyl methacrylate to methanol is 1:4-6; and the molar ratio of methyl methacrylate to ethylenediamine is 5-10:1.

[0012] Preferably, the methanol solution of methyl methacrylate in step (2) is added dropwise to the methanol solution of ethylenediamine at a dropping speed of 0.1-0.3 mL / s, and the temperature of the reaction system is controlled at 0-2°C during the dropping process.

[0013] Preferably, the standing time in step (2) is 20-40 minutes, and the standing temperature is 0-2°C.

[0014] Preferably, the reaction temperature in step (2) is 35-45° C., and the reaction time is 20-30 h.

[0015] Preferably, in step (2), methanol and excess methyl methacrylate are removed by rotary evaporation at a temperature of 50-55°C.

[0016] Preferably, in step (3), the mass ratio of N,N-diethylacrylamide, methacryloylethyl sulfobetaine, lauryl hydroxysulfobetaine and sodium p-styrene sulfonate is 10:3-5:2-3:1-2; and the mass ratio of deionized water to N,N-diethylacrylamide is 3-8:1.

[0017] Preferably, in step (3), the mass ratio of the dendrimer monomer to N,N-diethylacrylamide is 0.1-0.3:20.

[0018] Preferably, in step (4), the mass ratio of the ammonium cerium nitrate to N,N-diethylacrylamide is 0.005-0.05:20; the first reaction temperature is 40-50° C., and the first reaction time is 3-5 h.

[0019] Preferably, in step (4), the mass ratio of 2,2'-azobisisobutylamidine dihydrochloride to N,N-diethylacrylamide is 0.1-0.5:20; the second reaction temperature is 65-75° C., and the second reaction time is 2-4 h.

[0020] Preferably, the dialysis step in step (4) is as follows: the reaction solution obtained by the reaction is naturally cooled to room temperature, then transferred to a dialysis bag, and dialyzed and purified in deionized water, the molecular weight cutoff of the dialysis bag is 3000-5000Da, and the dialysis time is 12-36h; the freeze-drying temperature is -30~-20°C, and the freeze-drying time is 20-40h.

[0021] Preferably, according to the present invention, the temperature-responsive micellar shearing agent is prepared according to the following method: (i) adding isobutyl acrylate, Span-20 and Tween-60 into white oil and stirring until completely dissolved to obtain an oil phase solution; (ii) adding N-isopropylacrylamide, N-vinylcaprolactam and dimethyldiallylammonium chloride to deionized water and stirring evenly to obtain an aqueous phase solution; adding the aqueous phase solution to the oil phase solution under stirring and stirring to obtain an inverse emulsion; (iii) heating the inverse emulsion to a reaction temperature under stirring and nitrogen protection, and adding an initiator to initiate the reaction; after the reaction is completed, cooling is performed to obtain a temperature-responsive micellar shearing agent.

[0022] Preferably, in step (i), the mass ratio of isobutyl acrylate, Span-20 and Tween-60 is 10:3-5:0.5-2; the white oil is 3#, 5#, 7#, 10#, 15# or 20# white oil, and the mass ratio of the white oil to isobutyl acrylate is 4-8:1.

[0023] Preferably, in step (ii), the mass ratio of N-isopropylacrylamide, N-vinylcaprolactam and dimethyldiallylammonium chloride is 10:4-6:2-4; the mass ratio of deionized water to N-isopropylacrylamide is 3-5:1; and the mass ratio of N-isopropylacrylamide in the aqueous solution to isobutyl acrylate in the oil solution is 1:1.

[0024] Preferably, in step (ii), after the aqueous phase solution is added to the oil phase solution, the stirring time is 20-40 min and the stirring speed is 400-600 r / min.

[0025] Preferably, in step (iii), the initiator is a combination of potassium persulfate and sodium bisulfite, wherein the mass ratio of potassium persulfate to sodium bisulfite is 2:1; and the mass ratio of the initiator to N-isopropylacrylamide is 0.1-0.5:10.

[0026] Preferably, the reaction temperature in step (iii) is 70-80° C., and the reaction time is 5-7 h.

[0027] Preferably according to the present invention, the high temperature resistant strong adsorption plugging agent is obtained according to the raw materials and preparation method in Chinese patent document CN115651615A.

[0028] Preferably, according to the present invention, the nanocomposite polymer brush lubricant is prepared according to the following method: (I) adding citric acid monohydrate, urea and nano-graphite into deionized water, ultrasonicating to obtain a mixed solution, and subjecting the obtained mixed solution to a hydrothermal reaction; after the reaction is completed, cooling, centrifuging and freeze-drying to obtain composite nanoparticles; (II) Lauryl methacrylate, hydroxyethyl acrylate, 2-methacryloyloxyethyl phosphorylcholine and pentamethyldiethylenetriamine are added to N,N-dimethylformamide, stirred until completely dissolved, and then composite nanoparticles are added and ultrasonically dispersed uniformly; the temperature is raised to the reaction temperature under nitrogen protection, and azobisisobutyronitrile is added to react; after the reaction is completed, the mixture is cooled to obtain a nanocomposite polymer brush lubricant.

[0029] Preferably, the particle size of the nanographite in step (I) is 50-200 nm; the mass ratio of the citric acid monohydrate, urea and nanographite is 4:2-4:0.1-0.3; and the mass ratio of the deionized water to the citric acid monohydrate is 5-15:1.

[0030] Preferably, the temperature of the hydrothermal reaction in step (I) is 150-200° C., and the time of the hydrothermal reaction is 4-6 h.

[0031] Preferably, the cooling in step (I) is natural cooling to room temperature, the freeze-drying temperature is -30 to -20°C, and the freeze-drying time is 20 to 40 hours.

[0032] Preferably, in step (II), the mass ratio of lauryl methacrylate, hydroxyethyl acrylate, 2-methacryloyloxyethyl phosphorylcholine and pentamethyldiethylenetriamine is 10:4-6:2-4:0.1-1; the mass ratio of N,N-dimethylformamide to lauryl methacrylate is 3-10:1; and the mass ratio of the composite nanoparticles to lauryl methacrylate is 0.5-1.5:10.

[0033] Preferably, the mass ratio of azobisisobutyronitrile to lauryl methacrylate in step (II) is 0.05-0.5:10.

[0034] Preferably, in step (II), the reaction temperature is 70-80° C., and the reaction time is 5-7 h.

[0035] According to the preferred embodiment of the present invention, the high temperature resistant system stabilizer is a mixture of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride, wherein the mass ratio of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride in the mixture is 1:0.4-0.6:0.1-0.3; the molecular formula of the perfluoroalkyl betaine is C 15 H 15 F 17 N2O4S, its structural formula is shown below: .

[0036] According to the present invention, the method for preparing the above-mentioned 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following steps: Add high temperature resistant clay into water and stir for more than 24 hours, then add light diesel and high temperature resistant system stabilizer and stir for 1 hour, then add dendritic macromolecular filtration reducer, temperature responsive micelle shearing agent, high temperature resistant strong adsorption plugging agent and nano-composite polymer brush lubricant in sequence and stir evenly to obtain the 10,000-meter deep-ground oil and gas lubrication and drag reduction water-based drilling fluid.

[0037] Preferably, the method for preparing the 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following steps: Add water to a high-speed stirring cup, add high-temperature resistant clay under low-speed stirring, and stir at low speed for more than 24 hours; add light diesel and high-temperature resistant system stabilizer, and stir at high speed for 1 hour; add dendritic macromolecular filtration reducer, and stir at high speed for 20 minutes; add temperature-responsive micelle shearing agent, and stir at high speed for 20 minutes; add high-temperature resistant strong adsorption plugging agent, and stir at high speed for 20 minutes; add nano-composite polymer brush lubricant, and stir at high speed for 20 minutes to obtain a 10,000-meter deep-ground oil and gas lubrication and resistance reduction water-based drilling fluid; the rotation speed of the low-speed stirring is 1000-3000r / min, and the rotation speed of the high-speed stirring is 8000-10000r / min.

[0038] According to the present invention, the application of the above-mentioned 10,000-meter deep oil and gas lubricating and drag-reducing water-based drilling fluid is used in the drilling process of deep and ultra-deep oil and gas formations, which can increase the mechanical drilling speed, reduce drill bit wear, reduce drilling accidents such as differential pressure sticking, and reduce the drilling time and overall cost of 10,000-meter deep oil and gas wells; the deep and ultra-deep oil and gas formations include but are not limited to 10,000-meter deep formations.

[0039] Unless otherwise specified, the "parts" in the present invention are parts by weight.

[0040] The technical features and beneficial effects of the present invention are as follows: 1. The water-based drilling fluid of the present invention is added with a dendritic macromolecular fluid loss reducer, which is a macromolecular polymer with a multi-branched structure. Compared with traditional linear macromolecules, it has a lower viscosity effect, is convenient for controlling rheological properties under high-density conditions, and has a small mean square gyration radius, large molecular rigidity, and the molecular chain is not easy to entangle, which is conducive to its better performance under high temperature and high salt conditions. Each branch of the polymer can be connected with a plurality of clay particles or weighting material particles to form a high-strength three-dimensional grid structure in the drilling fluid, which is conducive to the suspension and dispersion of particles in the drilling fluid, so that the drilling fluid maintains good rheology while making the drilling fluid mud cake more compact, effectively reducing the filtration loss. On the one hand, the amphoteric betaine structure in the macromolecular branch chain has surface activity, can play a wetting role, and further promote the dispersion of the weighting material. On the other hand, the salt resistance of the drilling fluid is improved by polyelectrolytes.

[0041] 2. A temperature-responsive micellar shearing agent is added to the water-based drilling fluid of the present invention. The shearing agent is a temperature-responsive polymer material, which is an irregularly shaped micron-sized polymer particle at room temperature, and can be dispersed between the drilling fluid clay and the weighting agent, playing a certain role in plugging and synergistic filtration loss reduction. Under high temperature conditions, the shearing agent can be partially softened and wrapped on the drilling fluid grid, further enhancing the strength of the drilling fluid grid structure, effectively improving the shear force of the drilling fluid under the premise of low viscosity-increasing effect, maintaining a good dynamic-plastic ratio of the drilling fluid, improving the suspension ability of the drilling fluid to the weighting material, and enhancing the sedimentation stability of the high-density drilling fluid.

[0042] 3. The water-based drilling fluid of the present invention is added with a nanocomposite polymer brush lubricant, which is an organic-inorganic composite material. On the one hand, the large specific surface area of ​​the inorganic nanoparticles can make the lubricant form a more dense and uniform lubricating film on the surface of the drilling tool. On the other hand, the mutual displacement between the highly stretched polymer brush and the nanoparticles can form a rolling effect, further reducing friction. At the same time, the nanocomposite structure can enhance the temperature and salt resistance of the polymer brush, so that it can still play a good lubricating role under 240°C and saturated salt conditions.

[0043] 4. The base fluid of the drilling fluid system of the present invention is an oil-in-water microemulsion formed by water and light diesel under the action of a high-temperature resistant system stabilizer, and has better high-temperature resistance and lubricity coefficient than a simple water-based fluid. Adding high-temperature resistant clay improves the colloidal properties of the base fluid and provides more action sites for the treating agent. The dendritic macromolecular fluid loss reducer and the temperature-responsive micelle shearing agent synergistically form a strong grid structure in the drilling fluid that is resistant to ultra-high temperatures and high mineralization, and play a good role in reducing fluid loss, maintaining good rheology, and suspending weighting materials and cuttings under ultra-high temperature, high mineralization, and high density conditions for a long time. The high-temperature resistant strong adsorption plugging agent further blocks the pores and cracks in the mud cake and formation, reducing the amount of fluid loss. The nanocomposite polymer brush lubricant forms a lubricating film on the drill tool and mud cake, improving the lubrication ability of the drilling fluid and reducing drilling friction. With the synergistic effect of various treatment agents, the drilling fluid can have low viscosity, good lubrication performance and sedimentation stability as well as good rheological properties under the conditions of 240°C, saturated salt and high density. It can increase the mechanical drilling speed, reduce drill bit wear, reduce drilling accidents such as differential pressure sticking, and reduce the drilling time and overall cost of oil and gas wells deep to a depth of 10,000 meters. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention are further described below. According to the following examples, the present invention can be better understood. However, it is easy for those skilled in the art to understand that the specific material ratios, process conditions and results described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims. In the following examples and comparative examples, unless otherwise specified, the materials used are all commercially available, and the methods used are all conventional methods in the art.

[0045] Unless otherwise specified, the "parts" involved in the following preparation examples and embodiments are parts by weight.

[0046] Preparation Example 1 The dendritic macromolecular fluid loss reducer was prepared according to the following method: 1) Add 1.5 g of ethylenediamine and 7.5 g of methanol into a three-necked flask and stir thoroughly to obtain a methanol solution of ethylenediamine. Place the solution in an ice-water bath and cool it to 0°C under nitrogen protection.

[0047] 2) Weigh 20 g of methyl methacrylate and add it to 100 g of methanol to obtain a methanol solution of methyl methacrylate, and add the obtained methanol solution of methyl methacrylate dropwise into the three-necked flask described in step 1) using a constant flow pump, and control the dropping speed to 0.2 mL / s. During the dropping process, control the temperature of the reaction system to be 0-2° C.; after the dropwise addition is completed, let it stand at 0-2° C. for 30 minutes, and then place the reaction system at 40° C. for 24 hours; after the reaction is completed, use a rotary evaporator at 50-55° C. to remove methanol and excess methyl methacrylate to obtain a yellow viscous liquid as a dendritic monomer.

[0048] 3) 20 g of N,N-diethylacrylamide, 8 g of methacryloylethyl sulfobetaine, 5 g of lauryl hydroxysulfobetaine and 2 g of sodium p-styrene sulfonate were weighed and added into 100 g of deionized water, and then 0.2 g of the dendrimer monomer obtained in step 2) was added under ultrasonic conditions to obtain a monomer solution.

[0049] 4) The obtained monomer solution was transferred to another three-necked flask, heated to 45°C under nitrogen protection, 0.01g of ammonium cerium nitrate was added, reacted at 45°C for 4h, then heated to 70°C, 0.2g of 2,2'-azobisisobutylamidine dihydrochloride was added and continued to react at 70°C for 3h; then naturally cooled to room temperature, the obtained reaction solution was transferred to a dialysis bag (molecular weight cutoff of 3000Da), dialyzed in deionized water for 24h, and then freeze-dried (temperature -25°C, time for 24h) and crushed to obtain a white powdery solid, which is a dendritic macromolecular filtrate reducer.

[0050] Preparation Example 2 The temperature-responsive micellar shearing agent was prepared according to the following method: 1) Add 10g isobutyl acrylate, 4g Span-20 and 1g Tween-60 to 60g 20# white oil and stir until completely dissolved to obtain an oil phase solution.

[0051] 2) Add 10 g of N-isopropylacrylamide, 5 g of N-vinylcaprolactam and 3 g of dimethyldiallylammonium chloride to 40 g of deionized water and stir evenly to obtain an aqueous solution; add the aqueous solution to the oil phase solution of step (1) at a stirring speed of 500 r / min, and continue stirring at a stirring speed of 500 r / min for 30 minutes to obtain an inverse emulsion.

[0052] 3) Transfer the inverse emulsion to a three-necked flask, maintain a speed of 500 r / min, heat to 75°C with nitrogen, add 0.2 g potassium persulfate and 0.1 g sodium bisulfite to initiate the reaction, and react at 75°C for 6 hours; after the reaction is completed, cool naturally to room temperature, and the obtained milky white translucent liquid is the temperature-responsive micelle shearing agent.

[0053] Preparation Example 3 The nanocomposite polymer brush lubricant was prepared according to the following method: 1) 4 g of citric acid monohydrate, 3 g of urea and 0.2 g of nano-graphite (particle size of 100 nm) were added to 40 g of deionized water, and a dark brown translucent mixed solution was obtained by ultrasonic treatment. The mixed solution was transferred to a stainless steel hydrothermal autoclave lined with PPL and reacted at 180°C for 5 h. After naturally cooling to a room temperature, the reaction solution was centrifuged, and the precipitate obtained by centrifugation was freeze-dried at -25°C for 24 h to obtain composite nanoparticles.

[0054] 2) Add 10g of lauryl methacrylate, 5g of hydroxyethyl acrylate, 3g of 2-methacryloyloxyethyl phosphorylcholine and 0.5g of pentamethyldiethylenetriamine to 50g of N,N-dimethylformamide, stir until completely dissolved, then add 1g of the composite nanoparticles obtained in step 1), and ultrasonically disperse for 10 minutes to obtain a mixed solution; transfer the obtained mixed solution to a three-necked flask, heat it to 75°C under nitrogen protection, add 0.1g of azobisisobutyronitrile, and react at 75°C for 6h; after the reaction is completed, naturally cool to room temperature, and the obtained viscous liquid is the nanocomposite polymer brush lubricant.

[0055] Comparative Preparation Example 1 A method for preparing a linear macromolecular fluid loss reducer comprises the following steps: 1) Weigh 20 g of N,N-diethylacrylamide, 8 g of methacryloylethyl sulfobetaine, 5 g of lauryl hydroxysulfobetaine and 2 g of sodium p-styrene sulfonate, add them into 100 g of deionized water, stir evenly to obtain a monomer solution.

[0056] 2) The monomer solution was transferred to a three-necked flask, heated to 45°C under nitrogen protection, 0.01 g of ammonium cerium nitrate was added, the mixture was reacted at 45°C for 4 h, the temperature was raised to 70°C, 0.2 g of 2,2'-azobisisobutylamidine dihydrochloride was added, and the mixture was reacted at 70°C for 3 h; the mixture was then naturally cooled to room temperature, the reaction solution was transferred to a dialysis bag (molecular weight cutoff of 3000 Da), dialyzed in deionized water for 24 h, and then freeze-dried (temperature -25°C, time of 24 h) and crushed to obtain a white powdery solid, which was a linear macromolecular fluid loss reducer.

[0057] Comparative Preparation Example 2 A method for preparing a micellar polymer is as described in Preparation Example 2, except that the temperature-sensitive monomer N-isopropylacrylamide in the original formula is replaced with an equal mass of acrylamide, and the temperature-sensitive monomer N-vinylcaprolactam is replaced with an equal mass of N-vinylpyrrolidone. The specific synthesis method is: 1) Add 10g isobutyl acrylate, 4g Span-20 and 1g Tween-60 to 60g 20# white oil and stir until completely dissolved to obtain an oil phase solution.

[0058] 2) Add 10 g of acrylamide, 5 g of N-vinyl pyrrolidone and 3 g of dimethyldiallylammonium chloride to 40 g of deionized water and stir evenly to obtain an aqueous solution; add the aqueous solution to the oil phase solution of step (1) at a stirring speed of 500 r / min, and continue stirring at a stirring speed of 500 r / min for 30 minutes to obtain an inverse emulsion.

[0059] 3) The inverse emulsion was transferred to a three-necked flask, the rotation speed was maintained at 500 r / min, and the mixture was heated to 75°C with nitrogen. 0.2 g potassium persulfate and 0.1 g sodium bisulfite were added to initiate the reaction, and the reaction was carried out at 75°C for 6 h. After the reaction was completed, the mixture was naturally cooled to room temperature to obtain a micellar polymer.

[0060] Comparative Preparation Example 3 A preparation method of a polymer brush lubricant is as described in Preparation Example 3, except that the preparation and addition of composite nanoparticles are omitted. The specific synthesis method is: 1) Add 10g of lauryl methacrylate, 5g of hydroxyethyl acrylate, 3g of 2-methacryloyloxyethyl phosphorylcholine and 0.5g of pentamethyldiethylenetriamine to 50g of N,N-dimethylformamide, and stir until completely dissolved to obtain a mixed solution; transfer the obtained mixed solution to a three-necked flask, heat it to 75°C under nitrogen protection, add 0.1g of azobisisobutyronitrile, and react at 75°C for 6h; after the reaction is completed, cool it naturally to room temperature, and the obtained viscous liquid is the polymer brush lubricant.

[0061] The dendrimer fluid loss reducer, temperature-responsive micelle shear enhancer and nanocomposite polymer brush lubricant used in the examples and comparative examples were prepared according to the methods described in Preparation Examples 1-3, respectively.

[0062] Example 1 A 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid, comprising the following raw materials in parts by weight: 100 parts of water, 8 parts of light diesel, 2 parts of high-temperature resistant clay, 4 parts of dendritic macromolecular filtrate reducer, 3 parts of temperature-responsive micelle shearing agent, 3 parts of high-temperature resistant strong adsorption plugging agent, 4 parts of nanocomposite polymer brush lubricant, and 2 parts of high-temperature resistant system stabilizer; The light diesel is commercially available 0# diesel; The high temperature resistant clay is prepared according to the method described in Example 1 of Chinese patent document CN118374267A; The high temperature resistant strong adsorption plugging agent is prepared according to the method described in Example 1 of Chinese patent document CN115651615A; The high temperature resistant system stabilizer is a mixture of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride, wherein the mass ratio of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride in the mixture is 1:0.5:0.2; the molecular formula of the perfluoroalkyl betaine is C 15 H 15 F 17 N2O4S, the structural formula is as follows: .

[0063] The preparation method of the above-mentioned 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following steps: Add water into a high-speed stirring cup, add high-temperature resistant clay under low-speed stirring, and stir at low speed for 30 hours; add light diesel and high-temperature resistant system stabilizer, and stir at high speed for 1 hour; add dendritic macromolecular filtration reducer, and stir at high speed for 20 minutes; add temperature-responsive micelle shearing agent, and stir at high speed for 20 minutes; add high-temperature resistant strong adsorption plugging agent, and stir at high speed for 20 minutes; add nano-composite polymer brush lubricant, and stir at high speed for 20 minutes to obtain 10,000-meter deep-ground oil and gas lubrication and resistance reduction water-based drilling fluid F1; the rotation speed of the low-speed stirring is 2000 r / min, and the rotation speed of the high-speed stirring is 10000 r / min.

[0064] Example 2 A 10,000-meter deep underground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 5 parts of light diesel, 1 part of high-temperature resistant clay, 6 parts of dendritic macromolecular filtration reducer, 4 parts of temperature-responsive micelle shearing agent, 4 parts of high-temperature resistant strong adsorption plugging agent, 3 parts of nano-composite polymer brush lubricant, and 1 part of high-temperature resistant system stabilizer.

[0065] The other raw material types and the preparation method of the drilling fluid are the same as those in Example 1, and the 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid F2 is prepared.

[0066] Example 3 A 10,000-meter deep underground oil and gas lubrication and drag-reducing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 10 parts of light diesel, 4 parts of high-temperature resistant clay, 3 parts of dendritic macromolecular filtration reducer, 2 parts of temperature-responsive micelle shearing agent, 2 parts of high-temperature resistant strong adsorption plugging agent, 5 parts of nano-composite polymer brush lubricant, and 3 parts of high-temperature resistant system stabilizer.

[0067] The other raw materials and the preparation method of the drilling fluid are the same as those in Example 1, and the 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid F3 is prepared.

[0068] Comparative Example 1 A water-based drilling fluid is as described in Example 1, except that no light diesel is added and the other raw material compositions are the same as those in Example 1.

[0069] The preparation method of the water-based drilling fluid is as described in Example 1, except that the addition of light diesel is omitted to prepare the water-based drilling fluid DF1.

[0070] Comparative Example 2 A water-based drilling fluid is as described in Example 1, except that no dendritic macromolecular fluid loss reducer is added, and other raw material compositions are the same as those in Example 1.

[0071] The preparation method of the water-based drilling fluid is as described in Example 1, except that the dendritic macromolecular fluid loss reducer is omitted to prepare the water-based drilling fluid DF2.

[0072] Comparative Example 3 A water-based drilling fluid is as described in Example 1, except that no temperature-responsive micelle shear enhancer is added, and other raw material compositions are the same as those in Example 1.

[0073] The preparation method of the water-based drilling fluid is as described in Example 1, except that the addition of the temperature-responsive micelle shearing agent is omitted to prepare the water-based drilling fluid DF3.

[0074] Comparative Example 4 A water-based drilling fluid is as described in Example 1, except that no high temperature resistant strong adsorption plugging agent is added, and other raw material compositions are the same as those in Example 1.

[0075] The preparation method of the water-based drilling fluid is as described in Example 1, except that the addition of the high temperature resistant strong adsorption plugging agent is omitted to prepare the water-based drilling fluid DF4; Comparative Example 5 A water-based drilling fluid is as described in Example 1, except that no nanocomposite polymer brush lubricant is added, and other raw material compositions are the same as those in Example 1.

[0076] The preparation method of the water-based drilling fluid is as described in Example 1, except that the addition of the nanocomposite polymer brush lubricant is omitted to prepare the water-based drilling fluid DF5; Comparative Example 6 A water-based drilling fluid is as described in Example 1, except that no high temperature resistant system stabilizer is added, and the other raw material compositions are the same as those in Example 1.

[0077] The preparation method of the water-based drilling fluid is as described in Example 1, except that the addition of the high temperature resistant system stabilizer is omitted to prepare the water-based drilling fluid DF6; Comparative Example 7 A water-based drilling fluid is as described in Example 1, except that the dendritic macromolecular fluid loss reducer is replaced by the linear macromolecular fluid loss reducer prepared in Comparative Preparation Example 1 to prepare the water-based drilling fluid DF7.

[0078] Comparative Example 8 A water-based drilling fluid is as described in Example 1, except that the temperature-responsive micellar shearing agent is replaced by the micellar polymer prepared in Comparative Preparation Example 2 to prepare the water-based drilling fluid DF8.

[0079] Comparative Example 9 A water-based drilling fluid is as described in Example 1, except that the nanocomposite polymer brush lubricant is replaced by the polymer brush lubricant prepared in Comparative Preparation Example 3 to prepare the water-based drilling fluid DF9.

[0080] Test Example 1 Take 400 mL of the drilling fluids F1-F3 and DF1-DF9 respectively and add barite to make the density 1.8 g / cm 3 , add saturated salt (36wt% NaCl) and stir at 5000r / min for 20min, then put it into an aging tank and put it into a roller furnace. After constant temperature rolling at 240℃ for 16 hours, take it out and cool it to room temperature, and stir it at 5000rpm for 20min. Then, according to the petroleum and natural gas industry standard GB / T 16783.1-2014 "Field Test of Drilling Fluids in Petroleum and Natural Gas Industry Part 1: Water-based Drilling Fluids", the apparent viscosity (AV, mPa·s), plastic viscosity (PV, mPa·s), dynamic shear force (YP, Pa), API filtration loss FL of the above drilling fluid were measured. API , high temperature and high pressure filtration loss FL HTHP (240℃), the results are shown in Table 1.

[0081] Table 1 Drilling fluid rheological filtration performance test

[0082] It can be seen from the above data that under the synergistic effect of the fluid loss reducer, the shearing agent and the plugging agent, the 10,000-meter deep-ground oil and gas lubricating drag-reducing water-based drilling fluid of the present invention has good rheological and fluid loss properties. 3 The dynamic shear force under the conditions reached 15mPa, the dynamic plastic ratio was maintained at about 0.4, and the high temperature and high pressure filtration loss was only 11.8mL. The lack of key components or incorrect preparation methods of key materials will lead to a significant decrease in the performance of the drilling fluid, proving that only the drilling fluid prepared according to the raw materials, proportions and configuration methods disclosed in the present invention can exert excellent performance.

[0083] Test Example 2 The drilling fluids F1-F3 and DF1-DF9 were tested for lubrication properties.

[0084] Take 400mL of drilling fluid F1-F3 and DF1-DF9 respectively, and add barite to make the density reach 1.8g / cm 3 , add 36wt% NaCl, stir at 5000rpm for 20min, put it into an aging tank, put it in a roller furnace, roll it at a constant temperature of 240℃ for 16h, then cool it to room temperature, and stir it at 5000rpm for 20min to obtain the drilling fluid to be tested.

[0085] The extreme pressure lubrication coefficient of different test slurries was tested using an extreme pressure lubrication instrument. The extreme pressure lubrication coefficient calculation formula is as follows:

[0086] Where K is the correction coefficient, dimensionless; M0 is the friction of water, dimensionless; M1 is the friction of the test slurry, dimensionless; X is the extreme pressure lubrication coefficient, dimensionless.

[0087] The rotation and friction of the drill bit under the infiltration of drilling fluid during the drilling process were simulated, and the lubrication ability of the drilling fluid on the metal was tested using a four-ball tribometer. The test conditions were a rotation speed of 1200r / min, a load of 196N, and a test temperature of 75±2℃. The friction coefficients of different test slurries were tested.

[0088] The test results are shown in Table 2.

[0089] Table 2 Drilling fluid lubrication ability test

[0090] It can be seen from the data in Table 2 that under the action of the microemulsion and the lubricant, the drilling fluid system of the present invention has good lubrication ability, the extreme pressure lubrication coefficient is as low as 0.1301, and the four-ball friction coefficient is as low as 0.038. The fluid loss reducer and the shear enhancer can enhance the overall temperature and salt resistance of the drilling fluid, make the weighting material well dispersed, and synergistically improve the lubrication ability of the drilling fluid under high temperature, high salt and high density conditions.

[0091] Test Example 3 The drilling fluids F1-F3 were subjected to a weightability test.

[0092] Take 400mL of drilling fluid F1-F3 respectively and add barite to make the density reach 2.0g / cm 3 , 2.2g / cm 3 and 2.4 g / cm 3, add 36wt% NaCl, stir at 5000rpm for 20min, put into aging tank, put into roller furnace, roll at 240℃ for 16h, take out and cool to room temperature, stir at 5000rpm for 20min, and get drilling fluid to be tested. Then, according to the petroleum and natural gas industry standard GB / T 16783.1-2014 "Field test of drilling fluid in petroleum and natural gas industry Part 1: Water-based drilling fluid", the apparent viscosity (AV, mPa·s), plastic viscosity (PV, mPa·s), dynamic shear force (YP, Pa), API filtration loss FL of the drilling fluid to be tested were measured. API , high temperature and high pressure filtration loss FL HTHP (240℃), the results are shown in Table 3.

[0093] Table 3 Drilling fluid weighting capacity test

[0094] It can be seen from Table 3 that at a density of 2.0 g / cm 3 , 2.2g / cm 3 and 2.4 g / cm 3 Under the conditions, the drilling fluid maintains good rheological and filtration properties, indicating that the drilling fluid has good weighting capacity and can support the use of drilling fluid under high density conditions.

[0095] Test Example 4 Drilling fluids F1-F3 were subjected to sedimentation stability tests.

[0096] Take 400mL of drilling fluid F1-F3 respectively and add barite to increase the weight to 2.4g / cm 3 , add 36wt% NaCl, stir at 5000rpm for 20min, put into aging tank, put in roller furnace, stand still at 240℃ for 16h, 48h, and 72h, and record the density of the top of drilling fluid column (lower layer of free liquid) r t and the density of the bottom r b , the static sedimentation factor of the drilling fluid is calculated according to the following formula. Generally speaking, when the static sedimentation factor is greater than 0.50 and less than 0.52, it can be considered that the drilling fluid system has good sedimentation stability.

[0097]

[0098] In the formula SF is the static sedimentation factor, dimensionless; r t is the top density of drilling fluid, g / cm 3 ; r bis the bottom density of drilling fluid, g / cm 3 The test results are shown in Table 4.

[0099] Table 4 Drilling fluid sedimentation stability test

[0100] It can be seen from Table 4 that with the increase of aging time, the static sedimentation factor of the drilling fluid system always remains between 0.50 and 0.52, indicating that the drilling fluid system can maintain good sedimentation stability for a long time.

[0101] In summary, the lubricating and drag-reducing water-based drilling fluid for oil and gas at a depth of 10,000 meters of the present invention can enable the drilling fluid to have lower viscosity, good lubrication performance, sedimentation stability and good rheological properties under the conditions of 240°C, saturated salt and high density, and can meet the needs of oil and gas drilling at a depth of 10,000 meters.

[0102] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A water-based drilling fluid for oil and gas lubrication and drag reduction at a depth of 10,000 meters, characterized in that: The raw materials include the following parts by weight: 100 parts of water, 5-10 parts of light diesel, 1-4 parts of high temperature resistant clay, 3-6 parts of dendritic macromolecular fluid loss reducer, 2-4 parts of temperature responsive micelle shearing agent, 2-4 parts of high temperature resistant strong adsorption plugging agent, 3-5 parts of nanocomposite polymer brush lubricant, and 1-3 parts of high temperature resistant system stabilizer; The dendritic macromolecular fluid loss reducer is prepared according to the following method: (1) Place the methanol solution of ethylenediamine in an ice water bath and cool to 0-2°C under nitrogen protection; (2) adding a methanol solution of methyl methacrylate to a methanol solution of ethylenediamine, allowing the mixture to stand for a reaction; after the reaction is completed, removing methanol and excess methyl methacrylate to obtain a dendritic monomer; the molar ratio of methyl methacrylate to ethylenediamine is 5-10:1; (3) adding N,N-diethylacrylamide, methacryloylethyl sulfobetaine, lauryl hydroxysulfobetaine and sodium p-styrene sulfonate into deionized water, and then adding a dendritic monomer under ultrasonic conditions to obtain a monomer solution; the mass ratio of the N,N-diethylacrylamide, methacryloylethyl sulfobetaine, lauryl hydroxysulfobetaine and sodium p-styrene sulfonate is 10:3-5:2-3:1-2; the mass ratio of the dendritic monomer to N,N-diethylacrylamide is 0.1-0.3:20; (4) heating the monomer solution to a first reaction temperature under nitrogen protection, adding cerium ammonium nitrate to carry out a first reaction; then heating the monomer solution to a second reaction temperature, adding 2,2'-azobisisobutylamidine dihydrochloride to carry out a second reaction; after the reaction is completed, dialyzing and freeze-drying to obtain a dendrimer fluid loss reducer; The temperature-responsive micellar shearing agent is prepared according to the following method: (i) adding isobutyl acrylate, Span-20 and Tween-60 to white oil and stirring until completely dissolved to obtain an oil phase solution; the mass ratio of isobutyl acrylate, Span-20 and Tween-60 is 10:3-5:0.5-2; (ii) adding N-isopropylacrylamide, N-vinylcaprolactam and dimethyldiallylammonium chloride into deionized water and stirring evenly to obtain an aqueous solution; adding the aqueous solution into the oil phase solution under stirring and stirring to obtain an inverse emulsion; the mass ratio of the N-isopropylacrylamide, N-vinylcaprolactam and dimethyldiallylammonium chloride is 10:4-6:2-4; the mass ratio of the N-isopropylacrylamide in the aqueous solution to the isobutyl acrylate in the oil phase solution is 1:1; (iii) heating the inverse emulsion to a reaction temperature under stirring and nitrogen protection, and adding an initiator to initiate the reaction; after the reaction is completed, cooling is performed to obtain a temperature-responsive micelle shearing agent; The nanocomposite polymer brush lubricant is prepared according to the following method: (I) adding citric acid monohydrate, urea and nanographite into deionized water, ultrasonicating to obtain a mixed solution, and subjecting the obtained mixed solution to a hydrothermal reaction; after the reaction is completed, cooling, centrifuging and freeze-drying to obtain composite nanoparticles; the mass ratio of citric acid monohydrate, urea and nanographite is 4:2-4:0.1-0.3; the temperature of the hydrothermal reaction is 150-200°C, and the time of the hydrothermal reaction is 4-6h; (II) adding lauryl methacrylate, hydroxyethyl acrylate, 2-methacryloyloxyethyl phosphorylcholine and pentamethyldiethylenetriamine to N,N-dimethylformamide, stirring until completely dissolved, then adding composite nanoparticles, and uniformly dispersing by ultrasonication; heating to the reaction temperature under nitrogen protection, adding azobisisobutyronitrile, and reacting; after the reaction is completed, cooling, a nanocomposite polymer brush lubricant is obtained; the mass ratio of the lauryl methacrylate, hydroxyethyl acrylate, 2-methacryloyloxyethyl phosphorylcholine and pentamethyldiethylenetriamine is 10:4-6:2-4:0.1-1; the mass ratio of the composite nanoparticles to the lauryl methacrylate is 0.5-1.5:10; the light diesel is one or a combination of two or more of 0#, -10#, -20# and -35# diesel; The high temperature resistant clay is obtained by using the raw materials and preparation method in Chinese patent document CN118374267A; The high temperature resistant strong adsorption plugging agent is obtained according to the raw materials and preparation method in Chinese patent document CN115651615A; The high temperature resistant system stabilizer is a mixture of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride, wherein the mass ratio of perfluoroalkyl betaine, Span-85 and dioctadecyl dimethyl ammonium chloride in the mixture is 1:0.4-0.6:0.1-0.3; the molecular formula of the perfluoroalkyl betaine is C 15 H 15 F 17 N2O4S, its structural formula is shown below: 。 2. The 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: The mass ratio of ethylenediamine to methanol in the methanol solution of ethylenediamine in step (1) is 1:4-6; The mass ratio of methyl methacrylate to methanol in the methanol solution of methyl methacrylate in step (2) is 1:4-6; the methanol solution of methyl methacrylate is dropwise added to the methanol solution of ethylenediamine at a dropping speed of 0.1-0.3 mL / s, and the temperature of the reaction system is controlled to be 0-2°C during the dropping process; the standing time is 20-40 min, and the standing temperature is 0-2°C; the reaction temperature is 35-45°C, and the reaction time is 20-30 h; in step (2), methanol and excess methyl methacrylate are removed by rotary evaporation, and the rotary evaporation temperature is 50-55°C.

3. The 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: The mass ratio of deionized water to N,N-diethylacrylamide in step (3) is 3-8:1; In step (4), the mass ratio of ammonium cerium nitrate to N,N-diethylacrylamide is 0.005-0.05:20; the first reaction temperature is 40-50°C, and the first reaction time is 3-5h; the mass ratio of 2,2'-azobisisobutylamidine dihydrochloride to N,N-diethylacrylamide is 0.1-0.5:20; the second reaction temperature is 65-75°C, and the second reaction time is 2-4h; the dialysis step is: naturally cooling the reaction solution obtained by the reaction to room temperature, then transferring it to a dialysis bag, and dialysis purification in deionized water, the molecular weight cutoff of the dialysis bag is 3000-5000Da, and the dialysis time is 12-36h; the freeze-drying temperature is -30~-20°C, and the freeze-drying time is 20-40h.

4. The 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: The white oil in step (i) is 3#, 5#, 7#, 10#, 15# or 20# white oil, and the mass ratio of the white oil to isobutyl acrylate is 4-8:1; The mass ratio of deionized water to N-isopropylacrylamide in step (ii) is 3-5:1; in step (ii), after the aqueous phase solution is added to the oil phase solution, the stirring time is 20-40 minutes and the stirring speed is 400-600 r / min.

5. The 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: In step (iii), the initiator is a combination of potassium persulfate and sodium bisulfite, wherein the mass ratio of potassium persulfate to sodium bisulfite is 2:1; the mass ratio of the initiator to N-isopropylacrylamide is 0.1-0.5:10; the reaction temperature is 70-80° C., and the reaction time is 5-7 hours.

6. The 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: The particle size of the nanographite in step (I) is 50-200 nm; the mass ratio of the deionized water to the citric acid monohydrate is 5-15:1; the cooling is natural cooling to room temperature, the freeze-drying temperature is -30~-20°C, and the freeze-drying time is 20-40h.

7. The 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1 is characterized in that: In step (II), the mass ratio of N,N-dimethylformamide to lauryl methacrylate is 3-10:1; the mass ratio of azobisisobutyronitrile to lauryl methacrylate is 0.05-0.5:10; the reaction temperature is 70-80° C., and the reaction time is 5-7 hours.

8. The method for preparing the 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 1, characterized in that: The steps include: Add high temperature resistant clay into water and stir for more than 24 hours, then add light diesel and high temperature resistant system stabilizer and stir for 1 hour, then add dendritic macromolecular filtration reducer, temperature responsive micelle shearing agent, high temperature resistant strong adsorption plugging agent and nano-composite polymer brush lubricant in sequence and stir evenly to obtain the 10,000-meter deep-ground oil and gas lubrication and drag reduction water-based drilling fluid.

9. The method for preparing the 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid according to claim 8, characterized in that: The steps include: Add water to a high-speed stirring cup, add high-temperature resistant clay under low-speed stirring, and stir at low speed for more than 24 hours; add light diesel and high-temperature resistant system stabilizer, and stir at high speed for 1 hour; add dendritic macromolecular fluid loss reducer, and stir at high speed for 20 minutes; Add temperature-responsive micelle shearing agent and stir at high speed for 20 minutes; add high-temperature resistant strong adsorption plugging agent and stir at high speed for 20 minutes; add nano-composite polymer brush lubricant and stir at high speed for 20 minutes to obtain a 10,000-meter deep-ground oil and gas lubrication and drag-reducing water-based drilling fluid; the rotation speed of the low-speed stirring is 1000-3000 r / min, and the rotation speed of the high-speed stirring is 8000-10000 r / min.

10. The use of the 10,000-meter deep oil and gas lubrication and drag-reducing water-based drilling fluid as claimed in claim 1, characterized in that: Used in the drilling process of deep and ultra-deep oil and gas formations, wherein the deep and ultra-deep oil and gas formations are formations ten thousand meters deep.

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