High-temperature anti-sloughing agent for organic salt drilling fluid and preparation method thereof

Abstract

The application discloses a high-temperature anti-sloughing agent for organic salt drilling fluid and a preparation method thereof. The high-temperature anti-sloughing agent for organic salt drilling fluid is obtained by kneading reaction of the following raw materials: oil-soluble substances, quaternary ammonium salt, micro-nano materials and a liquid mixture. The weight ratio of the oil-soluble substances, the quaternary ammonium salt and the micro-nano materials is 20-40:25-35:10-20. The liquid mixture accounts for 10%-20% of the total weight of the raw materials, and the liquid mixture comprises solvents, emulsifiers and defoaming agents, and the weight ratio of the solvents, the emulsifiers and the defoaming agents is 0.5-1.0:0.5-1.0:0.5-1.0. The high-temperature anti-sloughing agent for organic salt drilling fluid can improve the plugging and anti-sloughing capacity of the organic salt drilling fluid at high temperatures, and can be used at an environment of 200 DEG C.

Description

Technical Field

[0001] This application relates to the field of drilling fluid treatment agents, and more particularly to a high-temperature anti-collapse agent for organic salt drilling fluid and its preparation method. Background Technology

[0002] Currently, when water-based drilling fluids encounter shale formations, the water absorption and expansion characteristics of shale can cause problems such as borehole narrowing, collapse, and spalling, and in severe cases, stuck pipe and buried drill strings. Therefore, to improve the inhibition properties of water-based drilling fluids, organic salt drilling fluids formulated with organic salt solutions as the base fluid have performed exceptionally well in field applications, significantly reducing the frequency of complex downhole accidents. Organic salts are the core of organic salt drilling fluid systems. Initially, they mainly consisted of sodium formate and potassium formate. With technological advancements in recent years, various organic acid salts such as cesium formate, potassium acetate, potassium citrate, potassium tartrate, ammonium acetate, ammonium citrate, ammonium tartrate, their quaternary ammonium salts, and their mixtures have also begun to be used in drilling and completion fluids. While organic salt drilling fluids exhibit strong inhibition properties, their plugging and anti-collapse capabilities are relatively weak, often resulting in leakage or collapse when encountering certain fractured formations. Therefore, research is needed on specialized anti-collapse agents for organic salt drilling fluids. There are many types of anti-collapse agents, with asphalt-based anti-collapse agents being the most effective. They mainly rely on high-temperature softening to enter the cracks and seal them. However, asphalt-based anti-collapse agents are produced through sulfonation, which requires the use of concentrated sulfuric acid, making them quite dangerous. Furthermore, asphalt-based anti-collapse agents have high fluorescence, which affects logging in exploratory wells and is therefore restricted by oilfields.

[0003] Currently, some oilfields use non-fluorescent white asphalt as an anti-collapse agent for organic salt drilling fluids. However, commercially available non-fluorescent white asphalt anti-collapse agents suffer from severe thickening, excessive foaming, and poor temperature resistance, showing little effect in environments above 150℃. CN104194743A discloses an anti-collapse agent for oilfield drilling fluids, which is formed by the reaction of higher fatty acids, higher carbon fatty alcohols, and polyols at high temperatures. It contains both oil-soluble and water-soluble components and has a certain softening point. It performs well in polymer drilling fluids, but its temperature resistance is poor, below 150℃. Summary of the Invention

[0004] This application provides a high-temperature anti-collapse agent for organic salt drilling fluid and its preparation method, which can improve the sealing and anti-collapse ability of organic salt drilling fluid at high temperatures and can be used in an environment of 200°C.

[0005] The following technical solution was adopted in this application:

[0006] This application provides a high-temperature anti-collapse agent for organic salt drilling fluids, obtained by kneading and reacting the following raw materials: oil-soluble substances, quaternary ammonium salts, micro / nano materials, and a liquid mixture. The weight ratio of the oil-soluble substances, quaternary ammonium salts, and micro / nano materials is 20-40:25-35:10-20. The liquid mixture accounts for 10%-20% of the total weight of the raw materials and includes a solvent, emulsifier, and defoamer, with a weight ratio of 0.5-1.0:0.5-1.0:0.5-1.0.

[0007] Furthermore, the oil-soluble substance includes at least one of rosin resin, glyceryl stearate, ethylene glycol stearate, microcrystalline wax, and C9 petroleum resin.

[0008] Furthermore, the quaternary ammonium salt includes at least one of polychitosan quaternary ammonium salt, polydimethyldiallyl quaternary ammonium salt, and acrylic fiber.

[0009] Furthermore, the micro- and nanomaterials include at least one of nano-calcium carbonate, ultrafine sepiolite, ultrafine attapulgite, and ultrafine magnesium oxide.

[0010] Furthermore, the solvents include No. 10 white oil and / or paraffin oil.

[0011] Furthermore, the emulsifier includes at least one of the following: phenobarbital O-25, lecithin, acetylacetonate diol, and Tween 80.

[0012] Furthermore, defoamers include silicone defoamers and / or phosphate defoamers.

[0013] This application also provides a method for preparing the above-mentioned high-temperature anti-collapse agent for organic salt drilling fluid, comprising the following steps:

[0014] Oil-soluble substances, quaternary ammonium salts, micro / nano materials, and liquid mixtures are kneaded and reacted at 50°C for 2-4 hours to obtain a high-temperature anti-collapse agent for organic salt drilling fluids.

[0015] Further, the oil-soluble substance, quaternary ammonium salt, micro / nano materials, and liquid mixture are kneaded at 50°C for 2-4 hours, including: adding solvent, emulsifier, and defoamer to a container and stirring until homogeneous to obtain a liquid mixture; adding the oil-soluble substance, quaternary ammonium salt, and micro / nano materials to a kneader, turning on heating and stirring, adjusting the kneader temperature to 50°C, adding the liquid mixture to the kneader, and kneading for 2-4 hours.

[0016] Further, the liquid mixture is sprayed into the kneader.

[0017] Compared with the prior art, this application has the following beneficial effects:

[0018] 1) The kneading reaction involved in the high-temperature anti-collapse agent for organic salt drilling fluid in this application mainly utilizes grafting, modification, and surface modification principles to combine oil-soluble substances with other components. When used in drilling fluid, this forms a "core-shell structure" with a hard core and a soft outer shell, enhancing the drilling fluid's sealing and anti-collapse capabilities. This high-temperature anti-collapse agent for organic salt drilling fluid can be used in environments up to 200℃. Furthermore, in a high-temperature organic salt environment, the organic salt has a synergistic effect on the anti-collapse agent. The organic salt and the "core-shell structure" anti-collapse agent are tightly adsorbed onto the clay surface, forming a dense mud cake, thereby protecting the wellbore. In summary, the high-temperature anti-collapse agent for organic salt drilling fluid in this application can improve the sealing and anti-collapse capabilities of organic salt drilling fluid at high temperatures and can be used in environments up to 200℃.

[0019] 2) The high-temperature anti-collapse agent of this application is a grayish-white or light yellow free-flowing powder or granules with a low fluorescence level. When used in organic salt drilling fluids, it can eliminate foam caused by salt activity, meeting the requirements for use in exploration and production wells. It has a slight viscosity-reducing effect in organic salt drilling fluids and can appropriately improve the flow pattern of drilling fluids. The product has a certain oil and gas reservoir protection effect and can be flowed back in subsequent fracturing or acidizing processes.

[0020] 3) The production process of the high-temperature anti-collapse agent for organic salt drilling fluid of this application does not involve drying or crushing, resulting in a short production cycle and easier implementation of green and environmentally friendly production. In addition, the production time of this application is short, the operation is convenient, and the production capacity is high. Detailed Implementation

[0021] The technical methods in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] Organic salt drilling fluids exhibit strong inhibition properties, but their ability to plug and prevent collapse is relatively weak, often resulting in leakage or collapse when encountering certain fractured formations. Currently, there are few suitable anti-collapse agents for organic salt drilling fluids. Traditional products, such as asphalt-based anti-collapse agents, require sulfonation with concentrated sulfuric acid during production, which is hazardous. Currently, some oilfields use non-fluorescent white asphalt as an organic salt drilling fluid anti-collapse agent, and some manufacturers' products suffer from severe thickening, foaming, and poor temperature resistance.

[0023] To address the aforementioned issues, embodiments of this application provide a high-temperature anti-collapse agent for organic salt drilling fluids, obtained by kneading and reacting the following raw materials: oil-soluble substances, quaternary ammonium salts, micro / nano materials, and liquid mixtures.

[0024] In the above raw materials, the weight ratio of oil-soluble substances, quaternary ammonium salts, and micro / nano materials is 20-40:25-35:10-20. That is, the amount of oil-soluble substances is 20-40 parts by weight, the amount of quaternary ammonium salts is 25-35 parts by weight, and the amount of micro / nano materials is 10-20 parts by weight.

[0025] The oil-soluble substance can be one or a mixture of several of the following: rosin resin, glyceryl stearate, ethylene glycol stearate, microcrystalline wax, and C9 petroleum resin. For example, the oil-soluble substance can be a mixture of microcrystalline wax and glyceryl stearate, a mixture of rosin resin and ethylene glycol stearate, or a mixture of glyceryl stearate, microcrystalline wax, and C9 petroleum resin.

[0026] When the oil-soluble substance is a mixture of the above-mentioned substances, the weight ratio of microcrystalline wax to glyceryl stearate can be 1.5–2.0:0.5–1.5, such as 1.5:0.5, 1.5:1.5, 2.0:0.5, 2.0:1.5, etc.; the weight ratio of rosin resin to ethylene glycol stearate can be 0.5–1.5:2.0–3.0, such as 0.5:2.0, 0.5:3.0, 1.5:2.0, 1.5: 3.0, etc.; the weight ratio of glyceryl stearate, microcrystalline wax and C9 petroleum resin can be 0.5~1.5:1.5~2.0:0.5~1.5, such as 0.5:1.5:0.5, 0.5:1.5:1.5, 0.5:2.0:0.5, 0.5:2.0:1.5, 1.5:1.5:0.5, 1.5:1.5:1.5, 1.5:2.0:0.5, 1.5:2.0:1.5, etc.

[0027] The amount of oil-soluble substance can be 20 parts by weight, 30 parts by weight, or 40 parts by weight, etc.

[0028] Quaternary ammonium salts can be one or a mixture of several of the following: polychitosan quaternary ammonium salt, polydimethyldiallyl quaternary ammonium salt, and acrylic fiber. For example, quaternary ammonium salts can be a mixture of polydimethyldiallyl quaternary ammonium salt and acrylic fiber, or a mixture of acrylic fiber and polychitosan quaternary ammonium salt, etc.

[0029] When the quaternary ammonium salt is a mixture of the above substances, the weight ratio of polydimethyl diallyl quaternary ammonium salt to acrylic fiber can be 0.5–1.5:0.5–1.5, such as 0.5:0.5, 0.5:1.5, 1.5:0.5, 1.5:1.5, etc.; the weight ratio of acrylic fiber to chitosan quaternary ammonium salt can be 1.5–2.5:0.5–1.5, such as 1.5:0.5, 1.5:1.5, 2.5:0.5, 2.5:1.5, etc.

[0030] The amount of quaternary ammonium salt can be 25 parts by weight, 30 parts by weight, or 35 parts by weight, etc.

[0031] Micro- and nanomaterials can be one or a mixture of several of the following: nano-calcium carbonate, ultrafine sepiolite, ultrafine attapulgite, and ultrafine magnesium oxide. For example, micro- and nanomaterials can be a mixture of ultrafine sepiolite, ultrafine attapulgite, and nano-calcium carbonate, or a mixture of nano-calcium carbonate, ultrafine magnesium oxide, and ultrafine attapulgite, etc.

[0032] When the micro / nano materials are a mixture of the above-mentioned substances, the weight ratio of ultrafine sepiolite, ultrafine attapulgite, and nano-calcium carbonate can be 0.5–1.5:1.5–2.0:0.5–1.5, such as 0.5:1.5:0.5, 0.5:1.5:1.5, 0.5:2.0:0.5, 0.5:2.0:1.5, 1.5:1.5:0.5, 1.5:1.5:1.5, 1.5:2.0:0.5, 1.5:2.0:1.5, etc.; the weight ratio of nano-calcium carbonate, ultrafine magnesium oxide, and ultrafine attapulgite can be...

[0033] 1.5~2.5:1.5~2.0:0.5~1.5, such as 1.5:1.5:0.5, 1.5:1.5:1.5, 1.5:2.0:0.5, 1.5:2.0:1.5.

[0034] 2.5:1.5:0.5, 2.5:1.5:1.5, 2.5:2.0:0.5, 2.5:2.0:1.5, etc.

[0035] The amount of micro / nano materials used can be 10 parts by weight, 15 parts by weight, or 20 parts by weight, etc.

[0036] Of the above raw materials, the liquid mixture accounts for 10%-20% of the total weight of the raw materials, such as 10%, 15%, 20%, etc. The liquid mixture is a mixture of solvent, emulsifier, and defoamer. In the above liquid mixture, the weight ratio of solvent, emulsifier, and defoamer is 0.5-1.0:0.5-1.0:0.5-1.0, such as 0.5:0.5:0.5, 0.5:0.5:1.0, 0.5:1.0:0.5, 0.5:1.0:1.0, 1.0:0.5:0.5, 1.0:0.5:1.0, 1.0:1.0:0.5, 1.0:1.0:1.0, etc.

[0037] The solvent can be No. 10 white oil and / or paraffin oil. For example, the solvent can be No. 10 white oil or a mixture of No. 10 white oil and paraffin oil.

[0038] The emulsifier can be a surfactant with an HLB value greater than 14. Specifically, it can be one or a mixture of several of the following: Pingpingjia O-25, lecithin, acetylenol, and Tween 80. For example, the emulsifier can be a mixture of Pingpingjia O-25 and lecithin, or a mixture of acetylenol and Tween 80.

[0039] When the emulsifier is a mixture of the above substances, the calculated HLB value of the mixed surfactant must exceed 14.

[0040] The defoamer can be a silicone defoamer and / or a phosphate defoamer. For example, the defoamer can be a silicone defoamer or a mixture of silicone defoamer and phosphate defoamer.

[0041] When the defoamer is a mixture of the two substances mentioned above, the weight ratio of the silicone defoamer to the phosphate defoamer can be 1.5 to 2.5: 0.5 to 1.5, such as 1.5: 0.5, 1.5: 1.5, 2.5: 0.5, 2.5: 1.5, etc.

[0042] High-temperature anti-collapse agents for organic salt drilling fluids can be produced by kneading and reacting at 50°C for 2-4 hours.

[0043] The embodiments of this application also provide a method for preparing the above-mentioned high-temperature anti-collapse agent for organic salt drilling fluid, comprising the following steps:

[0044] Oil-soluble substances, quaternary ammonium salts, micro / nano materials, and liquid mixtures are kneaded and reacted at 50°C for 2-4 hours to obtain a high-temperature anti-collapse agent for organic salt drilling fluids.

[0045] Specifically, this may include the following steps:

[0046] (1) Add solvent, emulsifier and defoamer to a container and stir evenly to obtain a liquid mixture.

[0047] The liquid mixture can be poured into a production spray bottle.

[0048] (2) Add oil-soluble substances, quaternary ammonium salts, and micro / nano materials to a kneader, turn on heating and stirring, and adjust the kneader temperature to 50°C. Add the liquid mixture to the kneader and knead for 2-4 hours.

[0049] In the above steps, the kneading machine is a kneading machine with a heating function.

[0050] The liquid mixture can be sprayed into the kneader using a production sprayer. The production sprayer can be a standalone sprayer, in which case the liquid mixture is manually fed into the kneader. Alternatively, the production sprayer can be an integrated sprayer on the kneader, in which case the liquid mixture is automatically fed into the kneader using a mechanical feeding method.

[0051] The stirring speed can be 100 to 150 rpm, such as 100 rpm, 120 rpm, 150 rpm, etc. The stirring method can be up-and-down tumbling stirring.

[0052] The kneading reaction can be preferably carried out for 2-2.5 hours, such as 2 hours or 2.5 hours.

[0053] The material can be metered and bagged after 2-4 hours of kneading reaction.

[0054] The high-temperature anti-collapse agent for organic salt drilling fluids in this application has low fluorescence, can improve the toughness of wellbore mud cake, effectively reduce the high-temperature and high-pressure filtration loss of organic salt drilling fluids, and is not prone to damaging the permeability recovery value of the production formation. It can be used in an environment of 200℃ and is suitable for exploration wells and development wells.

[0055] The high-temperature anti-collapse agent of this application is mainly used in organic salt drilling fluids. It specifically increases the sealing and anti-collapse ability of organic salt drilling fluids, and has a short production time, is easy to operate, has a high production capacity, and can be used in an environment of 200℃.

[0056] The high-temperature anti-collapse agent for organic salt drilling fluid of this application is used in organic salt drilling fluid, based on the total weight of organic salt drilling fluid, wherein the content of the high-temperature anti-collapse agent is 1% to 6%, preferably 2% to 5%.

[0057] The following detailed description is provided with reference to specific embodiments:

[0058] Example 1

[0059] Add 5 parts by weight of paraffin oil, 5 parts by weight of 0-25 acetylacetonate, 5 parts by weight of acetylacetonate diol, and 5 parts by weight of silicone defoamer to a container for every 100g of weight. Stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0060] Add 35 parts by weight of rosin resin, 15 parts by weight of chitosan quaternary ammonium salt, 10 parts by weight of acrylic fiber, and 20 parts by weight of ultrafine magnesium oxide into a kneader. Turn on the heating and stirring, and adjust the kneader temperature to 50°C. Spray the liquid mixture into the kneader through a production sprayer. Knead for 2 hours to obtain a high-temperature anti-collapse agent. Then, meter the material and bag it.

[0061] Example 2

[0062] Add 10 parts by weight of paraffin oil, 5 parts by weight of acetylacetonate diol, and 5 parts by weight of silicone defoamer to a container for every 100g of paraffin oil. Stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0063] Add 20 parts by weight of microcrystalline wax, 10 parts by weight of C9 petroleum resin, 10 parts by weight of glyceryl stearate, 30 parts by weight of acrylic fiber, 15 parts by weight of nano calcium carbonate, and 5 parts by weight of ultrafine attapulgite to a kneader. Turn on the heating and stirring, and adjust the kneader temperature to 50°C. Spray the liquid mixture into the kneader through a production sprayer. Knead for 2 hours to obtain a high-temperature anti-collapse agent. Then, meter the material and bag it.

[0064] Example 3

[0065] Add 5 parts by weight of paraffin oil, 5 parts by weight of Tween 80, and 5 parts by weight of phosphate defoamer to a container for every 100g of paraffin oil. Stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0066] Add 20 parts by weight of microcrystalline wax, 15 parts by weight of glyceryl stearate, 15 parts by weight of polydimethyldiallyl quaternary ammonium salt, 15 parts by weight of acrylic fiber, and 20 parts by weight of nano calcium carbonate into a kneader. Turn on the heating and stirring, and adjust the kneader temperature to 50°C. Spray the liquid mixture into the kneader through a production sprayer. Knead for 2 hours to obtain a high-temperature anti-collapse agent. Then, meter the material and bag it.

[0067] Example 4

[0068] Add 5 parts by weight of No. 10 white oil, 5 parts by weight of acetylation diol, and 5 parts by weight of phosphate defoamer to a container at a ratio of 100g per part by weight, stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0069] Add 30 parts by weight of rosin resin, 25 parts by weight of acrylic fiber, 10 parts by weight of polychidonic acid quaternary ammonium salt, 15 parts by weight of nano calcium carbonate, and 5 parts by weight of ultrafine magnesium oxide into a kneader. Turn on the heating and stirring, and adjust the kneader temperature to 50°C. Spray the liquid mixture into the kneader through a production sprayer. Knead for 2 hours to obtain a high-temperature anti-collapse agent. Then, meter the material and bag it.

[0070] Example 5

[0071] Add 5 parts by weight of No. 10 white oil, 5 parts by weight of acetylation diol, and 5 parts by weight of phosphate defoamer to a container at a ratio of 100g per part by weight, stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0072] Add 20 parts by weight of microcrystalline wax, 15 parts by weight of glyceryl stearate, 30 parts by weight of acrylic fiber, and 20 parts by weight of nano calcium carbonate to a kneader, turn on heating and stirring, and adjust the kneader temperature to 50°C. Spray the liquid mixture into the kneader through a production sprayer, knead for 2 hours to obtain a high-temperature anti-collapse agent, and then meter and bag it.

[0073] Example 6

[0074] Add 7.5 parts by weight of paraffin oil, 5 parts by weight of acetylenol, and 7.5 parts by weight of silicone defoamer to a container for every 100g of product. Stir well to obtain a liquid mixture, and then pour it into a production spray bottle.

[0075] 15 parts by weight of rosin resin, 20 parts by weight of ethylene stearate, 25 parts by weight of polydimethyldiallyl quaternary ammonium salt, 5 parts by weight of ultrafine sepiolite, 10 parts by weight of ultrafine attapulgite, and 5 parts by weight of nano calcium carbonate were added to a kneader. Heating and stirring were turned on, and the kneader temperature was adjusted to 50°C. The liquid mixture was sprayed into the kneader through a production sprayer. The kneading reaction was carried out for 2 hours to obtain a high-temperature anti-collapse agent. Then, the material was metered, discharged, and bagged.

[0076] Experimental Example 1

[0077] Base slurry composition:

[0078] (1) Freshwater base slurry: 350mL distilled water + 14.0g drilling fluid test slurry soil + 7.0g evaluation soil + 0.49g sodium carbonate, stir at high speed for 20min, and cure at room temperature for 24 hours. The drilling fluid test slurry soil and evaluation soil in the base slurry are commercially available products and comply with the industry standard "SY / T 5490-2016 Drilling Fluid Test Soil".

[0079] (2) 160℃ Organic Salt-Based Slurry: 350mL seawater + 1.5% sodium bentonite + 2% cutting agent + 3% filtration loss reducer BDF-200S + 3% fine calcium + 20% sodium formate + barite. The sodium bentonite is a commercially available product. The cutting agent is a modified silicate product. The filtration loss reducer BDF-200S is a low-viscosity acrylic polymer filtration loss reducer, a product of Tianjin Zhongyou Boxing Engineering Technology Co., Ltd.

[0080] The drilling fluid application performance of the products obtained in Examples 1-6 is evaluated below:

[0081] The products obtained in Examples 1-6 were added to the freshwater-based slurry at a dosage of 2%, and stirred at high speed for 20 minutes. The high-temperature and high-pressure filtration loss at 150°C and a pressure difference of 3.5 MPa was tested, and the results are shown in Table 1. In addition, the high-temperature and high-pressure filtration loss of the freshwater-based slurry at 150°C and a pressure difference of 3.5 MPa was tested to be 86 mL.

[0082] Table 1

[0083]

[0084]

[0085] The test performance of the products obtained in Examples 1-6 in organic salt-based slurry is shown in Table 2.

[0086] Table 2

[0087]

[0088] The performance of the products obtained in Examples 1-6 after aging in organic salt drilling fluid at 200°C for 16 hours is shown in Table 3.

[0089] Table 3

[0090]

[0091]

[0092] As can be seen from the table above, the products obtained in Examples 1-6 have a certain viscosity-reducing effect in drilling fluid, do not foam, have a certain defoaming function, have a significant effect on reducing filtration loss under high temperature and high pressure, and can be used in an environment of 200℃.

[0093] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made without departing from the spirit and scope of this application. The scope of protection claimed by this application is defined by the appended claims, specification, and their equivalents.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A high temperature anti-sloughing agent for an organic salt drilling fluid, characterized by comprising: The oil-soluble substance, the quaternary ammonium salt, the micro-nano material and the liquid mixture are kneaded at 50 DEG C for 2-4 hours to obtain the high-temperature anti-sloughing agent for organic salt drilling fluid. The oil-soluble substance, the quaternary ammonium salt, the micro-nano material and the liquid mixture are kneaded at 50 DEG C for 2-4 hours to obtain the high-temperature anti-sloughing agent for organic salt drilling fluid. The weight ratio of the oil-soluble substance, the quaternary ammonium salt and the micro-nano material is 20-40:25-35:10-20. The liquid mixture accounts for 10%-20% of the total weight of the raw materials, and the liquid mixture includes a solvent, an emulsifier and a defoaming agent, and the weight ratio of the solvent, the emulsifier and the defoaming agent is 0.5-1.0:0.5-1.0:0.5-1.

0. The oil-soluble substance includes at least one of rosin resin, glycerol stearate, ethylene glycol stearate, microcrystalline paraffin and C9 petroleum resin. The quaternary ammonium salt includes at least one of polyquaternary ammonium salt and polydimethyl diallyl quaternary ammonium salt. The micro-nano material includes at least one of nano calcium carbonate, super-fine sea bubble stone, super-fine attapulgite and super-fine magnesium oxide.

2. The high-temperature anti-sloughing agent for organic salt drilling fluid according to claim 1, wherein the solvent includes No. 10 white oil and / or paraffin oil.

3. The high-temperature anti-sloughing agent for organic salt drilling fluid according to claim 1, wherein the emulsifier includes at least one of Pingpingka O-25, lecithin, acetylenic diol and Tween 80.

4. The high-temperature anti-sloughing agent for organic salt drilling fluid according to claim 1, wherein the defoaming agent includes organic silicon defoaming agent and / or phosphate defoaming agent. The oil-soluble substance, the quaternary ammonium salt, the micro-nano material and the liquid mixture are kneaded at 50 DEG C for 2-4 hours to obtain the high-temperature anti-sloughing agent for organic salt drilling fluid.

6. The preparation method according to claim 5, wherein the oil-soluble substance, the quaternary ammonium salt, the micro-nano material and the liquid mixture are kneaded at 50 DEG C for 2-4 hours, including: The solvent, the emulsifier and the defoaming agent are added into a container and stirred uniformly to obtain the liquid mixture; 5. A method for preparing the organic salt high temperature anti-sloughing agent for drilling fluid according to any one of claims 1-4, characterized in that, The oil-soluble substance, the quaternary ammonium salt and the micro-nano material are added into a kneader, and heating and stirring are started, and the temperature of the kneader is adjusted to 50 DEG C, and the liquid mixture is added into the kneader, and kneaded for 2-4 hours.

7. The preparation method according to claim 6, wherein the liquid mixture is sprayed into the kneader. ​ ​ ​ ​ ​ ​

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