Oil-gas wall-fixing type water-based drilling fluid for ground with depth of myriameter as well as preparation method and application of water-based drilling fluid

Abstract

The invention provides a myriameter deep oil-gas wall-fixing type water-based drilling fluid as well as a preparation method and application thereof, and belongs to the technical field of drilling fluids. The myriameter deep oil gas wall-fixing type water-based drilling fluid is prepared from the following raw materials in parts by weight: 100 parts of water, 1-5 parts of a modified clay shear strength improving agent, 2-4 parts of a hydrophobic association polymer flow pattern regulator, 3-8 parts of a blocking agent, 2-5 parts of a hyperbranched polymer filtrate reducer and 1-3 parts of a cementation blocking type wall-fixing agent. The invention also provides a preparation method of the drilling fluid. The components such as the flow pattern regulator, the plugging agent, the filtrate reducer and the wall-fixing agent are mutually matched and synergistic, so that the drilling fluid can keep good rheological, filtration, plugging and inhibition performances for a long time under the conditions of 240 DEG C and saturated salt, has a strong wall-fixing effect, can effectively maintain the stability of the well wall of an oil-gas well in the depth of 10,000 meters, and has a wide application prospect. And well collapse, well leakage, blowout and other complex well drilling are prevented, and the drilling tool can be used for drilling oil and gas wells with the depth of ten thousand meters.

Description

Technical Field

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

[0002] Drilling fluid is called the "blood of drilling". It has functions such as stabilizing the well wall, carrying cuttings, and balancing formation pressure. It is an indispensable core engineering technology in oil and gas exploration and development, and is directly related to the success or failure of drilling and the production of oil and gas reservoirs. During the drilling process of 10,000-meter-deep oil and gas wells, the "four ultra-" harsh conditions of ultra-high temperature (>200℃), ultra-high pressure (>140MPa), ultra-high salt (formation fluid mineralization>200,000mg / L), and ultra-high stress (>160MPa) cause the rheology of the drilling fluid to decrease or even be lost, and the filtration loss to increase sharply. In addition, due to the complex formation conditions and the coexistence of multiple lithologies (mudstone, sandstone, dolomite, etc.), the well wall instability mechanism is complex. The existing water-based drilling fluid is difficult to stabilize the well wall, and the well wall is prone to collapse and peeling. The drilling risk is huge, and accidents such as well collapse, well leakage, and blowout occur frequently, which seriously hinder the exploration and development of oil and gas in the 10,000-meter-deep earth. It is urgent to develop a strong-wall water-based drilling fluid that can stabilize the well wall of oil and gas wells in the 10,000-meter depth.

[0003] Chinese patent documents CN117736707A and CN117946640A respectively disclose a 230°C high-salt-resistant high-density water-based drilling fluid and its preparation method and application, and a 230°C high-mineralization-resistant environmentally friendly water-based drilling fluid and its preparation method and application. These two drilling fluids show good rheological and filtration properties under 230°C high-salt conditions, and have certain plugging and inhibition properties, but do not show effective retention of performance at higher temperatures; Chinese patent document CN115466603A discloses a 240°C salt-resistant plugging water-based drilling fluid and its preparation method and application. The system plays an effective role in plugging and maintaining the stability of the well wall under ultra-high temperature conditions of 240°C through the synergistic effect of plugging agents and anti-collapse agents, but the polyacrylamide potassium salt inhibitor in the system is easily ineffective under high temperature and high salt conditions, and the mud shale formations encountered during drilling may cause hydration expansion and thus well wall instability.

[0004] The existing water-based drilling fluids generally have serious performance degradation under the ultra-high temperature and high mineralization conditions of oil and gas wells at a depth of 10,000 meters, and cannot meet the requirements of well wall stability in various complex lithology formations, making it difficult to meet the needs of oil and gas drilling at a depth of 10,000 meters. Therefore, it is urgent to develop a water-based drilling fluid that can stabilize the well wall of oil and gas at a depth of 10,000 meters, so as to effectively prevent the occurrence of drilling complications such as well collapse, well leakage, and blowout, and provide technical support for oil and gas drilling at a depth of 10,000 meters. Summary of the invention

[0005] In view of the shortcomings of the prior art, especially the problem that the current water-based drilling fluid in deep formations has insufficient wall-fixing ability and is difficult to maintain the stability of the wellbore walls of different lithology formations in oil and gas wells at a depth of 10,000 meters, the present invention provides a 10,000-meter deep oil and gas wall-fixing water-based drilling fluid and its preparation method and application. The present invention uses modified clay shearing agent, hydrophobic associating polymer flow type regulator, plugging agent, hyperbranched polymer filtration loss reducer and cementing plugging type wall-fixing agent as core components to construct a 10,000-meter deep oil and gas wall-fixing water-based drilling fluid. The drilling fluid can maintain good rheology, filtration loss, plugging and inhibition performance for a long time under the conditions of 240°C and saturated salt, can effectively maintain the stability of the wellbore walls of oil and gas wells at a depth of 10,000 meters, can effectively prevent the occurrence of drilling complications such as well collapse, well leakage, and blowout, and provide technical support for oil and gas drilling at a depth of 10,000 meters.

[0006] The present invention is achieved through the following technical solutions: A 10,000-meter deep underground oil and gas wall-fixing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 1-5 parts of modified clay shearing agent, 2-4 parts of hydrophobic associating polymer flow pattern regulator, 3-8 parts of plugging agent, 2-5 parts of hyperbranched polymer filtrate reducer, and 1-3 parts of cementitious plugging-type wall-fixing agent.

[0007] Preferably, according to the present invention, the modified clay shearing agent is prepared according to the following method: (1) Mixing magnesium aluminum hydrotalcite and a 1:1 type clay mineral, and adding the mixture into an ethanol aqueous solution to obtain a dispersion; (2) adding hexadecyltrimethylammonium bromide and dimethylaminopropyl methacrylamide to the dispersion obtained in step (1), stirring evenly, heating to the reaction temperature under nitrogen protection, adding an initiator, and conducting a constant temperature reaction under nitrogen protection; after the reaction is completed, centrifuging, washing, drying, and crushing to obtain a modified clay shearing agent.

[0008] Preferably, the magnesium aluminum hydrotalcite in step (1) is a carbonate-type magnesium aluminum hydrotalcite. More preferably, the chemical composition of the magnesium aluminum hydrotalcite is Mg6Al2(OH) 16 (CO3)·4H2O.

[0009] Preferably, the 1:1 type clay mineral in step (1) is a clay mineral composed of two different crystal lamellae in a 1:1 ratio, wherein the composition of the crystal lamellae includes but is not limited to silicon-oxygen tetrahedron, aluminum-oxygen octahedron, dioctahedral mica, and dioctahedral montmorillonite; and the mass ratio of the magnesium-aluminum hydrotalcite to the 1:1 type clay mineral is 0.1-0.3:1.

[0010] Preferably, the volume ratio of deionized water to anhydrous ethanol in the ethanol aqueous solution in step (1) is 1-3:1.

[0011] Preferably, the total mass concentration of magnesium aluminum hydrotalcite and 1:1 type clay mineral in the dispersion in step (1) is 5-10%.

[0012] Preferably, the mass of the hexadecyltrimethylammonium bromide in step (2) is 0.3-0.8% of the mass of the dispersion; the mass of the dimethylaminopropyl methacrylamide is 0.5-1.5% of the mass of the dispersion.

[0013] Preferably, the initiator in step (2) is ammonium persulfate or potassium persulfate, and the mass of the initiator is 0.001-0.01% of the mass of the dispersion.

[0014] Preferably, the reaction temperature in step (2) is 55-65° C., and the isothermal reaction time is 6-8 h.

[0015] Preferably, the washing in step (2) is to wash the solid obtained by centrifugation with deionized water for 3-5 times; and the drying is to dry at 80-100° C. for 8-12 hours.

[0016] Preferably, according to the present invention, the hydrophobically associating polymer flow pattern regulator is prepared according to the following method: (I) adding alkyl substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethylallylammonium chloride and 2-methyl-1-vinyl imidazole into water, stirring until uniformly dispersed, to obtain a monomer solution; (II) nitrogen is introduced into the monomer solution obtained in step (I), the temperature is raised to a first temperature, phenyltriethoxysilane is added, stirred until dissolved, the temperature is raised to a second temperature, azobisisobutylamidine hydrochloride and sodium bisulfite are added to initiate a reaction, and nitrogen is introduced to carry out a constant temperature reaction; after the reaction is completed, the solution is washed and dried to obtain a hydrophobic associating polymer flow type regulator.

[0017] Preferably, the alkyl-substituted acrylamide in step (I) is one or a combination of two or more of N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide and N-hydroxymethylacrylamide.

[0018] Preferably, the long-chain alkyl dimethyl allyl ammonium chloride in step (I) is a quaternary ammonium chloride compound, wherein the three substituents are two methyl groups and an allyl group, and the fourth substituent is a C10-C18 alkyl group; further preferably, the long-chain alkyl dimethyl allyl ammonium chloride is hexadecyl dimethyl allyl ammonium chloride or octadecyl dimethyl allyl ammonium chloride.

[0019] Preferably, in step (I), the molar ratio of the alkyl substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethyl allyl ammonium chloride and 2-methyl-1-vinyl imidazole is 1:0.2-0.4:0.05-0.15:0.05-0.15.

[0020] Preferably, the concentration of the monomer solution in step (I) is 20-40wt%; the monomers are alkyl-substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethylallylammonium chloride and 2-methyl-1-vinylimidazole.

[0021] Preferably, in step (II), the first temperature is 40-50° C.; and the mass of the phenyltriethoxysilane is 0.05-0.15% of the total mass of the monomers.

[0022] Preferably, in step (II), the mass of the azobisisobutylamidine hydrochloride is 0.1-1% of the total mass of the monomers; the mass of the sodium bisulfite is 0.05-0.15% of the total mass of the monomers.

[0023] According to the present invention, in step (II), the total mass of monomers refers to the total mass of alkyl-substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethyl allyl ammonium chloride and 2-methyl-1-vinylimidazole.

[0024] Preferably, in step (II), the second temperature is 70-80° C. and the constant temperature reaction time is 4-6 hours.

[0025] Preferably, in step (II), the washing is washing the reaction product with acetone for 3-5 times, and the drying is drying at 80-100° C. for 8-12 hours.

[0026] According to the present invention, the plugging agent is prepared according to the method of Chinese patent document CN115160513A.

[0027] Preferably, according to the present invention, the hyperbranched polymer fluid loss reducer is prepared according to the following method: (i) heating and melting trimethylolpropane under nitrogen protection; then adding a methanol solution of potassium methoxide to react; after the reaction is completed, removing excess methanol, heating to 90-100° C., adding glycidol, and reacting at a constant temperature to obtain hyperbranched glycidol; (ii) adding N,N-dimethylacrylamide, (3-acrylamidopropyl)trimethylammonium chloride, methyl allyl alcohol polyoxyethylene ether and the hyperbranched glycidol obtained in step (ii) into water, stirring at 40-45° C. under nitrogen protection until completely dissolved, then adding cerium ammonium nitrate aqueous solution to react; after the reaction is completed, adding ethanol to the reaction solution for precipitation, centrifuging, and purifying the obtained lower layer product to obtain a hyperbranched polymer fluid loss reducer.

[0028] Preferably, the heating in step (i) is heating to 70-80°C.

[0029] Preferably, the methanol solution of potassium methoxide in step (i) is obtained by dissolving potassium methoxide in methanol, and the mass ratio of potassium methoxide to methanol is 0.5-0.7:1; the mass ratio of potassium methoxide to trimethylolpropane is 0.1-0.2:1.

[0030] Preferably, in step (i), the temperature for reacting the potassium methoxide methanol solution is 70-80° C. and the reaction time is 20-40 min. After the reaction is completed, excess methanol in the reaction system is removed by vacuuming.

[0031] Preferably, in step (i), the mass ratio of glycidol to trimethylolpropane is 20-30:1; and the addition rate of glycidol is 0.1-0.2 mL / min.

[0032] Preferably, in step (i), the time for adding glycidol to react at a constant temperature is 4-6 hours.

[0033] Preferably, in step (ii), the mass ratio of N,N-dimethylacrylamide, (3-acrylamidopropyl)trimethylammonium chloride, methyl allyl alcohol polyoxyethylene ether and hyperbranched glycidol is 10:4-6:1-3:0.05-0.15; the mass ratio of N,N-dimethylacrylamide to water is 1:10-20; the structural formula of the methyl allyl alcohol polyoxyethylene ether is as follows, and the average molecular weight of the methyl allyl alcohol polyoxyethylene ether is 1000-4000.

[0034]

[0035] Methyl allyl alcohol polyoxyethylene ether Preferably, the concentration of the aqueous solution of cerium ammonium nitrate in step (ii) is 0.1-0.3 wt %, and the mass ratio of the aqueous solution of cerium ammonium nitrate to N,N-dimethylacrylamide is 4-6:10.

[0036] Preferably, the reaction temperature in step (ii) is 60-70° C., and the reaction time is 1-3 h.

[0037] Preferably, the purification step in step (ii) is as follows: dissolving the lower layer product obtained by centrifugation with water, adding ethanol for precipitation, and then centrifuging. After repeating the above steps 2-3 times, freeze-drying and crushing are performed to obtain a hyperbranched polymer fluid loss reducer. There is no specific requirement for the amount of ethanol for precipitation and the amount of water for dissolution, as long as the precipitation and dissolution processes can be completed. This is a commonly used method for purifying polymers in the art.

[0038] According to the present invention, the cementing and plugging type wall-fixing agent is prepared according to the method of Chinese patent document CN114716984A.

[0039] According to the present invention, the method for preparing the above-mentioned 10,000-meter deep underground oil and gas wall-solidifying water-based drilling fluid comprises the following steps: Add the modified clay shearing agent into water and stir for more than 24 hours, then add the hydrophobic associating polymer flow regulator, plugging agent, hyperbranched polymer filtrate reducer and cementing plugging type wall fixing agent, stir evenly to obtain the 10,000-meter deep underground oil and gas wall fixing water-based drilling fluid.

[0040] Preferably, according to the present invention, the specific preparation method comprises the following steps: Add water into a high-speed stirring cup, add modified clay shearing agent under low-speed stirring, and stir at low speed for more than 24 hours; add hydrophobic associating polymer flow type regulator, and stir at high speed for 20 minutes; add plugging agent, and stir at high speed for 20 minutes; add hyperbranched polymer filtration reducer, and stir at high speed for 20 minutes; add cementing plugging wall-fixing agent, and stir at high speed for 20 minutes to obtain a 10,000-meter deep-ground oil and gas wall-fixing 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.

[0041] According to the present invention, the above-mentioned 10,000-meter deep oil and gas solid-wall water-based drilling fluid is used in the drilling process of deep and ultra-deep oil and gas formations to maintain the stability of the wellbore of the oil and gas well, prevent the occurrence of drilling complications such as well collapse, blowout, and drill sticking, and ensure the smooth progress of deep and ultra-deep oil and gas drilling; the deep and ultra-deep oil and gas formations include but are not limited to 10,000-meter deep formations.

[0042] Unless otherwise specified, the "parts" in the present invention are parts by weight.

[0043] The technical features and beneficial effects of the present invention are as follows: 1. A specific modified clay shearing agent is added to the wall-fixing water-based drilling fluid of the present invention. The modified clay shearing agent of the present invention is a composite material combining a polymer and clay. The preferred 1:1 interlayer clay mineral (such as rectorite) of the present invention is easier to achieve intercalation modification than the commonly used 2:1 clay mineral (such as bentonite), forming a strongly electron-deficient and highly electrical structure, having good dispersibility, thixotropy, suspension and high-temperature stability, and effectively ensuring the suspension of weighting materials and drill cuttings by the drilling fluid under ultra-high temperature saturated salt conditions.

[0044] 2. A hydrophobic associating polymer flow regulator is added to the wall-fixing water-based drilling fluid of the present invention. The hydrophobic associating polymer flow regulator of the present invention is a zwitterionic copolymer with a hydrophobic associating structure, which has the functions of regulating the rheological properties of the drilling fluid and reducing filtration loss. The alkyl-substituted acrylamide provides a CC main chain with high bond energy, which improves the upper temperature limit of the overall polymer; the five-membered imidazole heterocycle improves the rigidity of the molecular chain, greatly improving the ability of the molecular chain to resist hydrolysis under ultra-high temperature and high salt conditions; the amphoteric structure of the betaine monomer enables the polymer to be closely adsorbed with the hydrotalcite and clay in the modified clay shearing agent, improving the efficiency of the action, and the sulfonic acid group brings a thicker hydration film, which has stable performance under ultra-high temperature and ultra-high pressure saturated salt conditions and effectively reduces the filtration loss; the hydrophobic long chain of the long-chain alkyl dimethyl allyl ammonium chloride enables the polymer to form intramolecular associations, enhances the viscosity-increasing effect of the polymer, and at the same time, as a cationic monomer, enables the polymer to have salt responsiveness, and can also maintain stable rheological properties under high salt conditions.

[0045] 3. The wall-fixing water-based drilling fluid of the present invention is added with a hyperbranched polymer fluid loss reducer. The hyperbranched polymer fluid loss reducer of the present invention is three-dimensional dendrite-shaped, has many branching points, and the molecular chain is not easy to entangle. The molecular chain has good adsorption capacity, strong rigidity, and large steric hindrance. It not only ensures that the polymer has a long-term structural stability under ultra-high temperature conditions, but also effectively resists the strong double-layer compression of salt ions on the molecular chain, so that the polymer can efficiently maintain the spatial extension state of the molecular chain under ultra-high temperature saturated salt conditions, thereby bringing a thicker hydration film, and the performance is stable under ultra-high temperature and ultra-high pressure saturated salt conditions, effectively reducing the amount of fluid loss. And the rich terminal cationic groups can form multi-point links with clay minerals in the formation, forming a polymer network on the well wall, and at the same time can effectively prevent the expansion of mud shale and maintain the stability of the well wall. And the viscosity of the hyperbranched polymer does not change with the increase of molecular weight, so that the hyperbranched polymer fluid loss reducer of the present invention has a lower viscosity effect than the traditional linear macromolecular fluid loss reducer, which is convenient for the configuration of the drilling fluid and the regulation of rheological properties.

[0046] 4. A specific plugging agent is added to the wall-fixing water-based drilling fluid of the present invention. The outer part of the plugging agent is a flexible polymer film with a large number of heterocyclic and benzene ring structures. The molecular chain has strong rigidity and large steric hindrance. It maintains high elasticity and toughness under ultra-high temperature saturated salt conditions, and can adapt to the size and shape of the mud cake and the pores in the formation to achieve efficient and dense filling. The internal rigid nano-silica serves as a supporting skeleton, which greatly increases the strength of the plugging agent after plugging, thereby effectively reducing the drilling fluid loss, preventing pressure transmission, and maintaining the stability of the well wall under ultra-high temperature saturated salt conditions.

[0047] 5. The wall-fixing water-based drilling fluid of the present invention is added with a cementing and plugging wall-fixing agent, which is an organic / inorganic composite material. On the one hand, it can effectively adhere to the pores of the well wall in water, bridge and plug the pores in the formation through the rigid silica part, and solidify by cementation; on the other hand, the wall-fixing agent is cemented and solidified on the surface of the well wall, which can effectively inhibit the hydration and dispersion of shale; on the third hand, the wall-fixing agent can be cemented and solidified in the process of drilling fluid loss to form mud cake, improve the density of mud cake, effectively reduce the loss of drilling fluid, and then help maintain or even enhance the strength of rock, and play a role in stabilizing the well wall of the broken formation.

[0048] 6. The modified clay shearing agent, hydrophobic associating polymer flow regulator and hyperbranched polymer fluid loss reducer in the wall-fixing water-based drilling fluid of the present invention cooperate to form a strong grid structure resistant to ultra-high temperature and high mineralization in the drilling fluid, and play a good role in reducing fluid loss, maintaining good rheology, suspending weighting materials and drill cuttings for a long time under ultra-high temperature, high mineralization and high density conditions; the plugging agent and cementing plugging type wall-fixing agent plug the pores and cracks in the mud cake and the formation, reduce the fluid loss, strengthen the broken formation well wall, prevent pressure transmission, and make the well wall more solid; at the same time, the hyperbranched polymer fluid loss reducer forms a layer of polymer film on the well wall, inhibits the hydration and expansion of clay minerals in the formation, and further ensures the stability of the well wall. With the synergistic effect of various treatment agents, the drilling fluid can maintain good rheological, filtration, plugging and inhibition properties for a long time under the conditions of 240°C and saturated salt, which has the effect of strengthening the wall. It can effectively maintain the stability of the wellbore of oil and gas wells at a depth of 10,000 meters, and can effectively prevent the occurrence of drilling complications such as well collapse, well leakage, and blowout. It can be used in drilling of 10,000-meter deep wells.

[0049] 7. The wall-fixing water-based drilling fluid system of the present invention does not contain sulfonated materials, has a simple configuration process, and does not release toxic and smelly gases under high temperature and high mineralization conditions. It has good environmental performance and can be promoted and used in areas with strict environmental protection requirements. It can provide technical support for maintaining my country's strategic task of 10,000-meter deep-ground oil and gas drilling. DETAILED DESCRIPTION

[0050] 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.

[0051] Unless otherwise specified, the "parts" involved in the following preparation examples and embodiments are parts by weight.

[0052] Preparation Example 1 The preparation method of the modified clay shearing agent comprises the following steps: 1) After mixing magnesium aluminum hydrotalcite and 1:1 type clay mineral in a mass ratio of 0.2:1, 16 g was weighed, and dispersed in 200 g of ethanol aqueous solution (deionized water: anhydrous ethanol = 2:1, v / v) by ultrasonic stirring to prepare a dispersion; The chemical composition of the magnesium aluminum hydrotalcite is Mg6Al2(OH) 16 (CO3)·4H2O; the 1:1 type clay mineral is a rectorite composed of dioctahedral mica and dioctahedral montmorillonite with a 1:1 regular interlayer.

[0053] 2) Add 1.08 g of hexadecyltrimethylammonium bromide and 2.16 g of dimethylaminopropyl methacrylamide to the above dispersion, stir thoroughly and disperse, then transfer to a three-necked flask, raise the temperature to 60°C through nitrogen, add 0.011 g of ammonium persulfate to initiate the reaction, keep stirring, and react at a constant temperature of 60°C for 7 hours under nitrogen protection.

[0054] 3) After the reaction is completed, the reaction product is centrifuged, and the obtained solid is washed 5 times with deionized water by centrifugation. The lower layer of precipitate is taken out and dried in an oven at 90°C for 12 hours and then crushed. The obtained solid is the modified clay shearing agent.

[0055] Preparation Example 2 The preparation method of the hydrophobically associating polymer flow pattern regulator comprises the following steps: 1) Mix N,N-diethylacrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt (CAS No.: 3637-26-1), octadecyldimethylallylammonium chloride and 2-methyl-1-vinylimidazole in a molar ratio of 1:0.3:0.1:0.1, weigh 30 g of the polymerization monomer, add it into 70 g of water, stir until fully dispersed, and obtain a monomer solution.

[0056] 2) Transfer the above monomer solution to a three-necked flask, heat it to 45°C through nitrogen, add 0.03g of phenyltriethoxysilane, stir thoroughly until dissolved, heat it to 75°C, add 0.15g of azobisisobutylamidine hydrochloride and 0.03g of sodium bisulfite to initiate the reaction, and react at 75°C under nitrogen protection for 5 hours.

[0057] 3) After the reaction is completed, the product is washed with acetone for 5 times, dried in an oven at 90°C for 12 hours, and then crushed to obtain a light yellow powder which is the hydrophobic associating polymer flow type regulator.

[0058] Preparation Example 3 The preparation method of the hyperbranched polymer fluid loss reducer comprises the following steps: 1) Add 2 g of trimethylolpropane into a three-necked flask, pass nitrogen gas, and stir to melt in an oil bath at 75°C.

[0059] 2) Weigh 0.3 g of potassium methoxide and dissolve it in 0.5 g of methanol. Use a syringe to add the resulting methanol solution of potassium methoxide into a three-necked flask. After reacting at 75°C for 30 min, vacuum the system to remove excess methanol.

[0060] 3) The reaction system was heated to 95°C, and 50 g of glycidol was added dropwise at a rate of 0.1 mL / min using a syringe pump. After the addition was completed, the reaction was continued at 95°C for 5 h to obtain hyperbranched glycidol.

[0061] 4) Add 150g of water, 10g of N,N-dimethylacrylamide, 5g of (3-acrylamidopropyl)trimethylammonium chloride, 2g of methyl allyl alcohol polyoxyethylene ether (average molecular weight of 2000) and 0.1g of hyperbranched glycidol into another three-necked flask, stir at 40℃ under nitrogen until completely dissolved, add 5g of 0.2wt% aqueous cerium ammonium nitrate solution with a syringe, heat to 65℃ and react for 2h.

[0062] 5) adding 50 mL of ethanol to the reaction solution obtained by the reaction for precipitation, and then centrifuging. The lower layer product obtained by centrifugation is purified to obtain a hyperbranched polymer fluid loss reducer; the purification step is: dissolving the lower layer product obtained by centrifugation with 200 mL of deionized water, adding 50 mL of ethanol for precipitation, and then centrifuging. After repeating the above steps for 3 times, freeze-drying (-35° C., 48 h) to obtain a white solid, which is crushed to obtain a hyperbranched polymer fluid loss reducer.

[0063] Comparative Preparation Example 1 A method for preparing modified clay is as described in Preparation Example 1, except that in step 1), the 1:1 type clay mineral is replaced with bentonite to obtain modified clay.

[0064] Comparative Preparation Example 2 A method for preparing a polymer flow pattern regulator is as described in Preparation Example 2, except that: in step 1), no octadecyl dimethyl allyl ammonium chloride is added to obtain the polymer flow pattern regulator.

[0065] Comparative Preparation Example 3 A method for preparing a linear polymer fluid loss reducer is as described in Preparation Example 3, except that: Add 150 parts of water, 10 parts of N,N-dimethylacrylamide, 5 parts of (3-acrylamidepropyl)trimethylammonium chloride and 2 parts of methyl allyl alcohol polyoxyethylene ether (average molecular weight is 2000) into a three-necked flask, stir until completely dissolved, add 0.1 parts of ammonium persulfate, heat to 65°C and react with nitrogen for 2 hours; other conditions are the same as those in Preparation Example 3, to obtain a linear polymer filtrate reducer.

[0066] The modified clay shearing agent, hydrophobically associating polymer flow pattern regulator and hyperbranched polymer fluid loss reducer used in the examples were prepared according to Preparation Examples 1-3, respectively.

[0067] The plugging agents used in the examples and comparative examples were prepared according to the method of Example 1 in Chinese patent document CN115160513A.

[0068] The cementing plugging type wall-fixing agent used in the examples and comparative examples was prepared according to the method of Example 1 in Chinese patent document CN114716984A.

[0069] Example 1 A 10,000-meter deep underground oil and gas wall-fixing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 2 parts of modified clay shearing agent, 3 parts of hydrophobic associating polymer flow pattern regulator, 5 parts of plugging agent, 4 parts of hyperbranched polymer filtrate reducer, and 2 parts of cementitious plugging wall-fixing agent.

[0070] The method for preparing the above-mentioned 10,000-meter deep underground oil and gas wall-solidifying water-based drilling fluid comprises the following steps: Add water into a high-speed stirring cup, add modified clay shearing agent under low-speed stirring, and stir at low speed for 30 hours; add hydrophobic associating polymer flow type regulator, and stir at high speed for 20 minutes; add plugging agent, and stir at high speed for 20 minutes; add hyperbranched polymer filtration reducer, and stir at high speed for 20 minutes; add cementing plugging wall solidifying agent, and stir at high speed for 20 minutes to obtain 10,000-meter deep-ground oil and gas wall solidifying 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.

[0071] Example 2 A 10,000-meter deep underground oil and gas wall-fixing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 5 parts of modified clay shearing agent, 4 parts of hydrophobic associating polymer flow pattern regulator, 3 parts of plugging agent, 2 parts of hyperbranched polymer filtrate reducer, and 1 part of cementitious plugging wall-fixing agent.

[0072] The other raw material types and the preparation method of the drilling fluid are the same as those in Example 1, and a water-based drilling fluid F2 for oil and gas wall solidification at a depth of 10,000 meters is obtained.

[0073] Example 3 A 10,000-meter deep underground oil and gas wall-fixing water-based drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 1 part of modified clay shearing agent, 2 parts of hydrophobic associating polymer flow pattern regulator, 8 parts of plugging agent, 5 parts of hyperbranched polymer filtrate reducer, and 3 parts of cementitious plugging-type wall-fixing agent.

[0074] The other raw material types and the preparation method of the drilling fluid are the same as those in Example 1, and a 10,000-meter deep underground oil and gas solid wall type water-based drilling fluid F3 is prepared.

[0075] Comparative Example 1 A water-based drilling fluid is as described in Example 1, except that no hydrophobic associating polymer flow regulator is added; other raw material compositions are the same as in Example 1.

[0076] The preparation method of the water-based drilling fluid is as described in Example 1, except that the step of adding the hydrophobic associating polymer flow pattern regulator is omitted; and the water-based drilling fluid DF1 is obtained.

[0077] Comparative Example 2 A water-based drilling fluid is as described in Example 1, except that no hyperbranched polymer fluid loss reducer is added; other raw material compositions are the same as in Example 1.

[0078] The preparation method of the water-based drilling fluid is as described in Example 1, except that the step of adding the hyperbranched polymer fluid loss reducer is omitted; and the water-based drilling fluid DF2 is obtained.

[0079] Comparative Example 3 A water-based drilling fluid is as described in Example 1, except that no plugging agent is added; other raw material compositions are the same as in Example 1.

[0080] The preparation method of the water-based drilling fluid is as described in Example 1, except that the step of adding the plugging agent is omitted; and the water-based drilling fluid DF3 is obtained.

[0081] Comparative Example 4 A water-based drilling fluid is as described in Example 1, except that no cementing plugging type wall-fixing agent is added; other raw material compositions are the same as those in Example 1.

[0082] The preparation method of the water-based drilling fluid is as described in Example 1, except that the step of adding a cementing plugging type wall-fixing agent is omitted; and the water-based drilling fluid DF4 is obtained.

[0083] Comparative Example 5 A water-based drilling fluid is as described in Example 1, except that the modified clay shearing agent is replaced by the modified clay prepared in Comparative Preparation Example 1; and a water-based drilling fluid DF5 is prepared.

[0084] Comparative Example 6 A water-based drilling fluid is as described in Example 1, except that the hydrophobic associating polymer flow pattern regulator is replaced by the polymer flow pattern regulator prepared in Comparative Preparation Example 2; and a water-based drilling fluid DF6 is prepared.

[0085] Comparative Example 7 A water-based drilling fluid is as described in Example 1, except that the hyperbranched polymer fluid loss reducer is replaced by the linear polymer fluid loss reducer prepared in Comparative Preparation Example 3; and the water-based drilling fluid DF7 is prepared.

[0086] Test Example 1 Take 400 mL of the drilling fluids F1-F3 and DF1-DF7 respectively and add barite to make the density 1.5 g / cm 3 , add saturated salt (36% 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.

[0087] Table 1 Drilling fluid performance test

[0088] It can be seen from the above data that the 10,000-meter deep-ground oil and gas solid wall water-based drilling fluid of the present invention has good rheological and filtration properties, and the high-temperature and high-pressure filtration loss under 240°C high temperature and saturated salt conditions is only 10.2 mL. The lack of key components or incorrect preparation methods of key materials will lead to a significant decline in the performance of the drilling fluid, proving that only drilling fluids prepared according to the raw materials, proportions and configuration methods published in the patent can exert excellent performance.

[0089] Test Example 2 The drilling fluids F1-F3 and DF1-DF7 were tested for sand bed plugging and core plugging performance.

[0090] Take 400mL of drilling fluid F1-F3 and DF1-DF7 respectively, and add barite to make the density reach 1.5g / cm 3 , add saturated salt (36% 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.

[0091] The instrument used for the sand bed filtration loss experiment is a visual medium-pressure sand bed plugging instrument. The sand particle size used is 80-100 mesh. The specific steps are as follows: 350 mL of sand is loaded into the sand filter tube and filled evenly; 200 mL of the drilling fluid to be tested is added to the top of the sand, and the gland is tightly covered. The gland mouth is sealed with a sealing ring; a measuring cylinder of a certain specification is placed under the sand filter tube to measure the filtration loss. First, the main gas valve of the nitrogen bottle is opened to provide a gas source. When the value of the pressure gauge connected to the upper end of the gland increases to 100 psi and stabilizes, the valve between the pressure gauge and the gland is opened for ventilation. After the stopwatch is used for 30 minutes, the filtration loss in the measuring cylinder is recorded (the filtration loss is the sand bed penetration depth or filtration loss volume). The results are shown in Table 2.

[0092] The core plugging rate was tested as follows: On the core flow tester, the initial forward standard brine permeability K1 of the rock sample was measured using a drilling fluid contamination holder. The core contamination holder was then removed and connected to a drilling fluid high temperature and high pressure dynamic comprehensive tester, and the above drilling fluid was used to positively plug the rock sample. The drilling fluid temperature was 80°C, the pressure difference was 3.5MPa, the confining pressure was 5MPa, and the shear rate was 150s. -1 After 30 minutes of damage, the core contamination holder was removed and connected to the core flow tester to measure the core forward standard brine permeability K2. The core plugging rate is:

[0093] The test results are shown in Table 2.

[0094] Table 2 Drilling fluid plugging performance test

[0095] It can be seen from Table 2 that the ten thousand meter deep underground oil and gas solid wall type water-based drilling fluid of the present invention has good plugging performance, the sand bed invasion depth is as low as 0.7 cm, and the core plugging rate reaches 96.9%.

[0096] Test Example 3 The drilling fluids F1-F3 and DF1-DF7 were tested for their inhibition and wall-fixing properties.

[0097] Sichuan Songlin red mud shale was selected as the test rock.

[0098] Take 30 grams of 10-mesh shale cuttings and put them into a mold (D=15mm), add 3mL of distilled water, press at 2Pa ​​for 5 minutes, take out the core, soak the core in different drilling fluids for 24 hours, and observe the integrity of the core. The results are shown in Table 3.

[0099] The shale was crushed and 6-10 mesh shale particles were screened. The shale was dried in a 202-0A electric constant temperature drying oven at 80°C for 6 h. After cooling in a dryer for 2 h, a rolling recovery rate experiment was carried out in 400 mL of the above-mentioned drilling fluids F1-F3 and DF1-DF7 (hot rolling at 240°C for 16 h). The experimental results are shown in Table 3.

[0100] Table 3 Drilling fluid inhibition and wall solidification performance test

[0101] It can be seen that the 10,000-meter deep underground oil and gas wall-fixing water-based drilling fluid of the present invention has good inhibition and wall-fixing properties, can effectively maintain the stability of the artificial shale mold core, and the shale recovery rate is as high as 97.1%.

[0102] Test Example 4 The drilling fluids F1-F3 were subjected to long-term aging tests.

[0103] Take 400mL of drilling fluid F1-F3 and add barite to 1.5g / cm 3 , add saturated salt (36% NaCl), stir at 5000rpm for 20min, put into aging tank, put into roller furnace, roll at 240℃ for 3 days, 5 days and 7 days, 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 4.

[0104] Table 4 Long-term aging test of drilling fluid

[0105] As can be seen from Table 4, with the increase of aging time, the viscosity of the drilling fluid system has decreased, but it can still maintain good shear force, indicating that the drilling fluid still has good grid structure strength. In addition, the drilling fluid always maintains a low filtration loss. The high-temperature and high-pressure filtration loss after aging at 240℃ for 7 days is only 17.0mL, indicating that the drilling fluid has the ability to be stable for a long time.

[0106] In summary, the water-based drilling fluid for oil and gas wall solidification at a depth of 10,000 meters of the present invention can maintain good rheological, filtration, plugging and inhibition properties for a long time under high temperature and high salt conditions, play a strong wall solidification effect, and can meet the needs of oil and gas drilling at a depth of 10,000 meters.

[0107] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0108] 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.

[0109] In addition, various embodiments of the present invention may be arbitrarily combined, and 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 in a 10,000-meter-deep well, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of water, 1-5 parts of modified clay shearing agent, 2-4 parts of hydrophobic associating polymer flow pattern regulator, 3-8 parts of plugging agent, 2-5 parts of hyperbranched polymer fluid loss reducer, and 1-3 parts of cementing plugging type wall fixing agent; The modified clay shearing agent is prepared according to the following method: (1) Mixing magnesium aluminum hydrotalcite and 1:1 type clay mineral, adding them into ethanol aqueous solution to obtain a dispersion; the magnesium aluminum hydrotalcite is carbonate type magnesium aluminum hydrotalcite; the 1:1 type clay mineral is a clay mineral composed of two different crystal sheets in a ratio of 1:1, and the composition of the crystal sheets is silicon oxygen tetrahedron, aluminum oxygen octahedron, dioctahedral mica or dioctahedral montmorillonite; the mass ratio of the magnesium aluminum hydrotalcite to the 1:1 type clay mineral is 0.1-0.3:1; (2) adding hexadecyltrimethylammonium bromide and dimethylaminopropyl methacrylamide to the dispersion obtained in step (1), stirring evenly, heating to the reaction temperature under nitrogen protection, adding an initiator, and conducting a constant temperature reaction under nitrogen protection; after the reaction is completed, centrifuging, washing, drying, and crushing to obtain a modified clay shearing agent; The hydrophobically associating polymer flow pattern regulator is prepared according to the following method: (I) adding alkyl substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethyl allyl ammonium chloride and 2-methyl-1-vinyl imidazole into water, stirring until uniformly dispersed, to obtain a monomer solution; the alkyl substituted acrylamide is one or a combination of two or more of N,N-dimethyl acrylamide, N,N-diethyl acrylamide, N-isopropyl acrylamide and N-hydroxymethyl acrylamide; the long-chain Alkyl dimethyl allyl ammonium chloride is a quaternary ammonium chloride compound, wherein three substituents are two methyl groups and an allyl group, and the fourth substituent is a C10-C18 alkyl group; the molar ratio of the alkyl substituted acrylamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, long-chain alkyl dimethyl allyl ammonium chloride and 2-methyl-1-vinyl imidazole is 1:0.2-0.4:0.05-0.15:0.05-0.15; (II) introducing nitrogen into the monomer solution obtained in step (I), raising the temperature to a first temperature, adding phenyltriethoxysilane, stirring until dissolved, raising the temperature to a second temperature, adding azobisisobutylamidine hydrochloride and sodium bisulfite to initiate a reaction, and introducing nitrogen to carry out a constant temperature reaction; after the reaction is completed, washing and drying to obtain a hydrophobic associating polymer flow type regulator; The hyperbranched polymer fluid loss reducer is prepared according to the following method: (i) heating and melting trimethylolpropane under nitrogen protection; then adding a methanol solution of potassium methoxide to react; after the reaction is completed, removing excess methanol, heating to 90-100° C., adding glycidol, and reacting at a constant temperature to obtain hyperbranched glycidol; the mass ratio of potassium methoxide to trimethylolpropane is 0.1-0.2:1; the mass ratio of glycidol to trimethylolpropane is 20-30:1; (ii) adding N,N-dimethylacrylamide, (3-acrylamidepropyl)trimethylammonium chloride, methyl allyl alcohol polyoxyethylene ether and the hyperbranched glycidol obtained in step (ii) into water, stirring at 40-45° C. under nitrogen protection until completely dissolved, and then adding an aqueous solution of cerium ammonium nitrate to react; after the reaction is completed, adding ethanol to the reaction solution for precipitation, centrifuging, and purifying the obtained lower layer product to obtain a hyperbranched polymer fluid loss reducer; the mass ratio of N,N-dimethylacrylamide, (3-acrylamidepropyl)trimethylammonium chloride, methyl allyl alcohol polyoxyethylene ether and hyperbranched glycidol is 10:4-6:1-3:0.05-0.15; The plugging agent is prepared according to the method of Chinese patent document CN115160513A; The cementing and plugging type wall-fixing agent is prepared according to the method of Chinese patent document CN114716984A.

2. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: The chemical composition of the magnesium aluminum hydrotalcite in step (1) is Mg6Al2(OH) 16 (CO3)·4H2O; the volume ratio of deionized water to anhydrous ethanol in the ethanol aqueous solution is 1-3:1; the total mass concentration of magnesium aluminum hydrotalcite and 1:1 type clay mineral in the dispersion is 5-10%.

3. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: In step (2), the mass of hexadecyltrimethylammonium bromide is 0.3-0.8% of the mass of the dispersion; the mass of dimethylaminopropyl methacrylamide is 0.5-1.5% of the mass of the dispersion; the initiator is ammonium persulfate or potassium persulfate, and the mass of the initiator is 0.001-0.01% of the mass of the dispersion; the reaction temperature is 55-65°C, and the constant temperature reaction time is 6-8h; the washing is to wash the solid obtained by centrifugation with deionized water for 3-5 times; and the drying is to dry at 80-100°C for 8-12h.

4. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: In step (I), the long-chain alkyl dimethyl allyl ammonium chloride is hexadecyl dimethyl allyl ammonium chloride or octadecyl dimethyl allyl ammonium chloride; and the concentration of the monomer solution is 20-40 wt%.

5. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: In step (II), the first temperature is 40-50° C.; the mass of the phenyltriethoxysilane is 0.05-0.15% of the total mass of the monomer; the mass of the azobisisobutylamidine hydrochloride is 0.1-1% of the total mass of the monomer; the mass of the sodium bisulfite is 0.05-0.15% of the total mass of the monomer; The second temperature is 70-80°C; the constant temperature reaction time is 4-6 hours; the washing is washing the reaction product with acetone for 3-5 times; the drying is drying at 80-100°C for 8-12 hours.

6. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: The heating in step (i) is heating to 70-80° C.; the methanol solution of potassium methoxide is obtained by dissolving potassium methoxide in methanol, and the mass ratio of potassium methoxide to methanol is 0.5-0.7:1; In step (i), the temperature for the reaction of adding the methanol solution of potassium methoxide is 70-80° C. and the reaction time is 20-40 min. After the reaction is completed, the excess methanol in the reaction system is removed by vacuuming; The rate of adding glycidol in step (i) is 0.1-0.2 mL / min; the time for adding glycidol for constant temperature reaction is 4-6 hours.

7. The ten thousand meter deep underground oil and gas wall solid water-based drilling fluid according to claim 1 is characterized in that: In step (ii), the mass ratio of N,N-dimethylacrylamide to water is 1:10-20; the average molecular weight of the methyl allyl alcohol polyoxyethylene ether is 1000-4000; the concentration of the cerium ammonium nitrate aqueous solution is 0.1-0.3wt%, and the mass ratio of the cerium ammonium nitrate aqueous solution to N,N-dimethylacrylamide is 4-6:10; The reaction temperature in step (ii) is 60-70° C., and the reaction time is 1-3 hours. The purification step comprises: dissolving the lower layer product obtained by centrifugation with water, adding ethanol for precipitation, and then centrifuging. The above steps are repeated 2-3 times, and then freeze-dried and crushed to obtain a hyperbranched polymer fluid loss reducer.

8. The method for preparing the ten-thousand-meter deep-ground oil and gas wall-solidifying water-based drilling fluid according to claim 1, characterized in that: The steps include: Add the modified clay shearing agent into water and stir for more than 24 hours, then add the hydrophobic associating polymer flow regulator, plugging agent, hyperbranched polymer filtrate reducer and cementing plugging type wall fixing agent, stir evenly to obtain the 10,000-meter deep underground oil and gas wall fixing water-based drilling fluid.

9. The method for preparing the ten-thousand-meter deep-ground oil and gas solid-wall water-based drilling fluid according to claim 8, characterized in that: The specific preparation method comprises the following steps: Add water into a high-speed stirring cup, add modified clay shearing agent under low-speed stirring, and stir at low speed for more than 24 hours; add hydrophobic associating polymer flow type regulator, and stir at high speed for 20 minutes; add plugging agent, and stir at high speed for 20 minutes; add hyperbranched polymer filtration reducer, and stir at high speed for 20 minutes; add cementing plugging wall-fixing agent, and stir at high speed for 20 minutes to obtain a 10,000-meter deep-ground oil and gas wall-fixing 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.

10. The use of the 10,000-meter deep oil and gas solid wall water-based drilling fluid of claim 1 in the drilling process of deep and ultra-deep oil and gas formations, characterized in that: Used to maintain the stability of the oil and gas well wall, the deep and ultra-deep oil and gas formation is a formation ten thousand meters deep.

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