Solid phase scavenger for oil-based drilling fluid, preparation method and application

Abstract

The present application relates to a kind of solid phase scavenger for oil-based drilling fluid.The main problem to be solved is that the flocculation effect of the existing oil-based drilling fluid flocculant is poor due to poor oil solubility and other reasons, which makes it difficult to remove harmful solid phase of oil-based drilling fluid. The weight fractions of the raw materials are as follows: 14-24 parts of lipophilic monomer, 2-8 parts of silicon-containing monomer, 14-30 parts of acrylamide, 4-7 parts of cationic monomer, 0.1-0.2 parts of initiator, and 1-4 parts of emulsifier. The preparation method is as follows: (1) add the lipophilic monomer, cationic monomer and emulsifier to white oil, stir until dissolved to obtain the first reaction solution; (2) add acrylamide and silicon-containing monomer to water, mix and stir evenly to form the second reaction solution; (3) mix the above two reaction solutions to make an emulsion; (4) start the polymerization reaction to obtain the product. The solid phase scavenger has high temperature stability, dispersibility, rheological property control ability and high molecular flocculation efficiency.

Description

Technical Field

[0001] This invention relates to the field of petrochemicals, and in particular to a solid phase remover for oil-based drilling fluids, its preparation method, and its application. Background Technology

[0002] Oil-based drilling fluids possess excellent inhibition, lubrication, and high-temperature resistance properties, and are widely used in the development of unconventional and complex oil and gas. They have effectively ensured the industrial development of shale oil and gas and low-grade oil and gas reservoirs in my country, improved my country's oil and gas self-sufficiency, and played an important role in enhancing my country's energy security and promoting the high-quality development of the oil and gas industry.

[0003] Oil-based drilling fluids are reused due to their high cost and the fact that the oil phase is hazardous waste. After drilling, the remaining oil-based drilling fluid is diluted and reused in drilling. With each reuse, the content of harmful solids (rock cuttings) in the system gradually increases. Simultaneously, these harmful solids are repeatedly ground down at the bottom of the well, reducing their particle size to below 10 μm, making them difficult to remove by centrifugation. Therefore, the content of harmful solids in the system gradually accumulates, causing a significant increase in drilling fluid viscosity and shear, which is difficult to control and seriously threatens safe drilling.

[0004] Harmful solids in water-based drilling fluids can be removed through selective flocculation, which agglomerates the harmful solids. Further removal can be achieved through screening and centrifugation. This provides a reference for the removal of harmful solids in oil-based drilling fluids, suggesting the development of flocculants to remove these harmful solids.

[0005] A search revealed relevant patent literature: CN109652026A discloses a flocculating flow pattern regulator for oil-based drilling fluids. This product is a type of suspension that regulates the flow pattern of oil-based drilling fluids and flocculates rock cuttings particles within them. This method can flocculate micro- and nano-dispersed particles in the system, but overall, the flocculation effect is relatively limited.

[0006] CN113292731B discloses a flocculant for removing cuttings from oil-based drilling fluids, its preparation method, and its application. The product is prepared by graft polymerization of prepolymer A and prepolymer B in the presence of a third-party solvent. It is a pale yellow, viscous liquid. This flocculant exhibits selective flocculation of cuttings in oil-based drilling fluids. When used with solids control equipment, it can effectively enhance the removal of fine cuttings at the micro-nano level, although its flocculation effect is relatively limited.

[0007] US Patent 7,338,608 B2 discloses a method for selectively removing cuttings from oil-based drilling fluids using a polymer synthesized via water-in-oil emulsion polymerization. The polymer contains at least one water-soluble monomer, synthesized from acrylamide, 2-acryloyloxyethyltrimethylammonium chloride, and N,N'-methylenebisacrylamide via water-in-oil emulsion polymerization. Since the polymer's external phase is oil, it can disperse in oil-based drilling fluids, adsorbing and trapping solid phases to achieve flocculation. However, this product is insoluble in the oil phase, thus its flocculation effect is relatively limited. Summary of the Invention

[0008] This invention provides a solid phase remover for oil-based drilling fluids to overcome the problem in the prior art where existing oil-based drilling fluid flocculants have poor flocculation effects due to poor oil solubility, making it difficult to remove harmful solid phases from oil-based drilling fluids. The purpose of this invention is to propose a solid phase remover for oil-based drilling fluids that simultaneously possesses high-temperature stability, dispersibility, rheological property control capabilities, and polymeric flocculation effects. The siloxane groups exhibit a certain polarity, allowing them to form a network structure in the system, thereby altering the system's rheology and simultaneously possessing polymeric flocculation effects. These two effects enhance the removal of harmful solid phases from oil-based drilling fluids and the control of system performance. This invention also provides a method for preparing the solid phase remover for oil-based drilling fluids and its application.

[0009] To achieve the above objectives, the first aspect of the present invention provides a solid phase remover for oil-based drilling fluids, the raw material components and the weight parts of each component being as follows: 14-24 parts of lipophilic monomer, 2-8 parts of silicon-containing monomer, 14-30 parts of acrylamide, 4-7 parts of cationic monomer, 0.1-0.2 parts of initiator, and 1-4 parts of emulsifier.

[0010] Preferably, the lipophilic monomer is any one of hexadecyl acrylate, hexadecyl acrylate, or styrene.

[0011] Preferably, the lipophilic monomer is hexadecyl acrylate.

[0012] Preferably, the silicon-containing monomer is any one of (dimethylaminoethyl methacrylate)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, or 1,1-di(trimethylsiloxy)-2-trimethylsilylethylene.

[0013] Preferably, the cationic monomer is a quaternary ammonium salt monomer or an imidazole monomer.

[0014] Preferably, the quaternary ammonium salt monomer is any one of vinyl quaternary ammonium salt, dimethyl diallyl ammonium chloride, or acrylamide alkyl quaternary ammonium salt monomer.

[0015] Preferably, the initiator is any one of azobisisobutyronitrile, ammonium persulfate, or potassium persulfate.

[0016] Preferably, the emulsifier is sPan 80.

[0017] A second aspect of this invention provides a method for preparing a solid phase remover for oil-based drilling fluids, comprising the following steps:

[0018] (1) Add the lipophilic monomer, cationic monomer and emulsifier to the solvent in proportion, stir until dissolved, and obtain the first reaction solution;

[0019] (2) Add acrylamide and silicon-containing monomers to water and mix and stir evenly to form a second reaction solution;

[0020] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0021] (4) Heat the above reaction solution while passing nitrogen gas through it. After the temperature stabilizes, add the initiator to the emulsion to start the polymerization reaction.

[0022] (5) Continue the reaction for 6 to 10 hours, and the product obtained is the target solid phase scavenger.

[0023] Preferably, the solvent in step (1) is white oil.

[0024] Preferably, the weight ratio of the lipophilic monomer, cationic monomer, emulsifier and white oil in step (1) is 14-24:4-7:1-3:90.

[0025] Preferably, the weight ratio of acrylamide, silicon-containing monomer and water in step (2) is 30:2-8:45-50.

[0026] Preferably, the heating temperature of the reaction solution in step (4) is 55-75°C.

[0027] The third aspect of this invention provides the application of a solid phase remover for oil-based drilling fluids in oil-based drilling fluids.

[0028] The present invention has at least the following beneficial effects:

[0029] This article provides a method for preparing a solid phase remover for oil-based drilling fluids, which has the following advantages:

[0030] (1) This product is a high molecular polymer that has a high molecular adsorption-bridging effect on the solid phase, thereby achieving flocculation of the solid phase of oil-based drilling fluid.

[0031] (2) After the product is dissolved in the system, it can change the rheological properties of the system. With the use of oil-based drilling fluid, the performance of the system can be continuously improved, which is beneficial to the safety of the drilling process.

[0032] (3) The product has a simple manufacturing process and is easy to mass-produce.

[0033] Field applications demonstrate that, in rheological evaluation, the addition of a solid phase remover to an oil-based drilling fluid system exhibits significant improvements, specifically in lower plastic viscosity and higher shear stress. This phenomenon is primarily due to the introduction of γ-aminopropyltriethoxysilane, which provides siloxy groups, giving the molecules a certain degree of polarity within the system. This polarity facilitates the formation of a three-dimensional network structure in the oil-based system, thereby improving its rheological properties. Regarding particle size evaluation, the addition of the solid phase remover to the oil-based drilling fluid resulted in significant flocculation in the evaluated white oil suspension. After treatment, the particle size increased dramatically from 4 μm to over 210 μm, indicating that the solid phase remover plays a crucial role in promoting solid particle aggregation. After further processing the oil-based drilling fluid through flocculation and sieving, the solid phase remover prepared in this invention was added, which caused the solid particles to flocculate and aggregate to a greater extent. After sieving, the content of solid particles was reduced from 54.3% without the remover to below 45.3%, proving the effectiveness of the solid phase remover. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used in the following examples are commercially available unless otherwise specified.

[0036] This invention is not limited to the specific embodiments listed below. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any modifications or alterations made to the design structure and concept of this invention fall within the protection scope of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0037] A solid phase remover for oil-based drilling fluids, the raw material components and the weight parts of each component are as follows:

[0038] The mixture contains 14-24 parts of lipophilic monomer, 2-8 parts of silicon-containing monomer, 14-30 parts of acrylamide, 4-7 parts of cationic monomer, 0.1-0.2 parts of initiator, and 1-4 parts of emulsifier.

[0039] The lipophilic monomer is any one of hexadecyl acrylate, hexadecyl acrylate, or styrene.

[0040] The lipophilic monomer is hexadecyl acrylate.

[0041] The silicon-containing monomer is any one of (dimethylaminoethyl methacrylate)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, or 1,1-bis(trimethylsiloxy)-2-trimethylsilylethylene.

[0042] The cationic monomer is a quaternary ammonium salt monomer or an imidazole monomer.

[0043] The quaternary ammonium salt monomer is any one of vinyl quaternary ammonium salt, dimethyl diallyl ammonium chloride, or acrylamide alkyl quaternary ammonium salt monomer.

[0044] The initiator is any one of azobisisobutyronitrile, ammonium persulfate, or potassium persulfate.

[0045] The emulsifier is sPan 80.

[0046] A method for preparing a solid phase remover for oil-based drilling fluids includes the following steps:

[0047] (1) Add the lipophilic monomer, cationic monomer, and emulsifier to the solvent in proportion, and stir until dissolved to obtain the first reaction solution. The weight ratio of the lipophilic monomer, cationic monomer, emulsifier, and white oil is 14-24:4-7:1-3:90.

[0048] (2) Add acrylamide and silicon-containing monomer to water and mix and stir evenly to form a second reaction solution. The weight ratio of acrylamide, silicon-containing monomer and water is 30:2-8:45-50.

[0049] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0050] (4) Heat the above reaction solution to 55-70°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add an initiator to the emulsion to start the polymerization reaction.

[0051] (5) Continue the reaction for 6 to 10 hours, and the product obtained is the target solid phase scavenger.

[0052] Example 1:

[0053] A method for preparing a solid phase remover for oil-based drilling fluids includes the following steps:

[0054] (1) Add 16g hexadecyl acrylate, 5g dimethyl diallyl ammonium chloride and 4g emulsifier to 90g white oil and stir until dissolved to obtain the first reaction solution;

[0055] (2) Add 8g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0056] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0057] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0058] (5) Continue the reaction for 8 hours, and the product is the target solid phase scavenger.

[0059] Example 2:

[0060] A method for preparing a solid phase remover for oil-based drilling fluids is described in Example 1, except that hexadecyl acrylate is replaced with styrene. The specific preparation method is as follows:

[0061] (1) Add 16g styrene, 5g dimethyl diallyl ammonium chloride and 4g emulsifier to 90g white oil and stir until dissolved to obtain the first reaction solution;

[0062] (2) Add 8g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0063] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0064] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0065] (5) Continue the reaction for 8 hours, and the product is the target solid phase scavenger.

[0066] Example 3:

[0067] A method for preparing a solid phase remover for oil-based drilling fluids is as described in Example 1, except that: the amount of dimethyl diallyl ammonium chloride is reduced to 3g, the amount of γ-aminopropyltriethoxysilane is reduced to 6g, and the reaction time is reduced to 6h; the specific preparation method is as follows:

[0068] (1) Add 16g hexadecyl acrylate, 3g dimethyl diallyl ammonium chloride and 4g emulsifier to 90g white oil and stir until dissolved to obtain the first reaction solution;

[0069] (2) Add 6g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0070] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0071] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0072] (5) Continue the reaction for 6 hours, and the product is the target solid phase scavenger.

[0073] Example 4:

[0074] A method for preparing a solid phase remover for oil-based drilling fluids is described in Example 1, except that the amount of dimethyl diallyl ammonium chloride added is 7g, and the reaction time is extended to 10h; the specific preparation method is as follows:

[0075] (1) Add 16g hexadecyl acrylate, 7g dimethyl diallyl ammonium chloride and 4g emulsifier to 90g white oil and stir until dissolved to obtain the first reaction solution;

[0076] (2) Add 6g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0077] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0078] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0079] (5) Continue the reaction for 10 hours, and the product is the target solid phase scavenger.

[0080] Comparative Example 1:

[0081] A method for preparing a solid phase remover for oil-based drilling fluids is described in Example 1, except that dimethyl diallyl ammonium chloride is not added; the specific preparation method is as follows:

[0082] (1) Add 16g of hexadecyl acrylate and 4g of emulsifier to 90mL of white oil and stir until dissolved to obtain the first reaction solution;

[0083] (2) Add 8g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0084] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0085] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0086] (5) Continue the reaction for 8 hours, and the product is the target solid phase scavenger.

[0087] Comparative Example 2:

[0088] A method for preparing a solid phase remover for oil-based drilling fluids is described in Example 1, except that γ-aminopropyltriethoxysilane is not added; the specific preparation method is as follows:

[0089] (1) Add 16g hexadecyl acrylate, 5g dimethyl diallyl ammonium chloride and 4g emulsifier to 90mL white oil and stir until dissolved to obtain the first reaction solution;

[0090] (2) Add 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0091] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0092] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0093] (5) Continue the reaction for 8 hours, and the product is the target solid phase scavenger.

[0094] Comparative Example 3:

[0095] A method for preparing a solid phase remover for oil-based drilling fluids is described in Example 1, except that the amount of dimethyl diallyl ammonium chloride is increased to 10g; the specific preparation method is as follows:

[0096] (1) Add 16g hexadecyl acrylate, 10g dimethyl diallyl ammonium chloride and 4g emulsifier to 90mL white oil and stir until dissolved to obtain the first reaction solution;

[0097] (2) Add 8g of r-aminopropyltriethoxysilane and 14g of acrylamide to 45mL of water and stir until dissolved to obtain the second reaction solution;

[0098] (3) Mix the first reaction solution and the second reaction solution to form an emulsion;

[0099] (4) Heat the above reaction solution to 60°C, and purge with nitrogen gas during the process. After the temperature stabilizes, add 0.2g of ammonium persulfate to the emulsion to start the polymerization reaction.

[0100] (5) Continue the reaction for 8 hours, and the product is the target solid phase scavenger.

[0101] The solid phase removers for oil-based drilling fluids prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated in the following tests.

[0102] Evaluation Example 1

[0103] Rheological performance evaluation

[0104] 1.1 Preparation of drilling fluid system: 320ml 0 # Diesel fuel, 3g organic soil, 6g primary emulsifier, 6g secondary emulsifier, 8g oxidized asphalt, 16g calcium oxide, 80ml 30% calcium chloride aqueous solution;

[0105] 1.2 Diesel fuel meets national standard 0 # Diesel fuel; organic clay, primary emulsifier, secondary emulsifier, oxidized asphalt, and wetting agent were provided by Hubei Hanko New Technology Co., Ltd.; calcium oxide was provided by Sinopharm.

[0106] 1.3 Seven types of solid phase removers for oil-based drilling fluids, as described in Examples 1-4 and Comparative Examples 1-3, were prepared and added to the drilling fluid system;

[0107] 1.4 Drilling fluid aging treatment: The drilling fluid samples were aged using a roller heating furnace at a temperature of 160℃ for 16 hours.

[0108] 1.5 Rheological property test: After aging, the drilling fluid was stirred at 10000 r / min for 20 min, and the rheological parameters (plastic viscosity PV and dynamic shear force YP) of the prepared drilling fluid were tested according to GBT 16783.2-2014.

[0109] Evaluation Example 2

[0110] Particle size changes before and after flocculation

[0111] The inferior solid phase material was prepared by simulating the inferior solid phase using evaluation soil: 6g of evaluation soil was added to 100mL of white oil, and then 1.5g of phospholipid was added. The mixture was stirred at 10,000r / min for 20min to ensure that the evaluation soil was well dispersed and suspended in the oil phase. 3g of the seven oil-based drilling fluid solid phase removers mentioned in Examples 1-4 and Comparative Examples 1-3 were added to each of the seven inferior solid phase materials. The size of the evaluation soil was measured using a focused beam reflectometer while stirring at 200r / min.

[0112] Evaluation Example 3

[0113] Evaluation of flocculation and screening effect

[0114] The oil-based drilling fluid sample was taken from Well WeiX, with a density of 2.17 g / cm³. 3The solid content was measured to be 54.3% using a solids content analyzer (Qingdao Tongchun, ZNG-50), forming 7 oil-based drilling fluid samples. 1.5% of the solids removal agents for oil-based drilling fluids from Examples 1-4 and Comparative Examples 1-3 (7 samples in total) were added to each sample. The mixture was stirred at 200 rpm for 10 minutes, then heated to 65°C and sieved using a 200-mesh standard sieve. The solid content of each sieved drilling fluid sample was then measured using a solids content analyzer at 425°C.

[0115] Table 1 shows the rheological properties, particle size, and solid content of harmful solid phases in oil-based drilling fluids after treatment with solid phase removers.

[0116] Table 1

[0117] category PV / (mPa·s) YP / (Pa) Median particle size / μm Solid content / % Original rock core / / / / Evaluation of soil / / 4 / Unflocculated oil-based drilling fluid 65 7 / 54.3 Example 1 50 9 285 42.5 Example 2 54 7.5 231 42.9 Example 3 55 8 210 45.3 Example 4 56 8 229 44.2 Comparative Example 1 62 6 14 54.6 Comparative Example 2 60 5 173 48.1 Comparative Example 3 60 5.5 19 53.2

[0118] As shown in Table 1, in the rheological evaluation, the oil-based drilling fluid solids removers prepared in Examples 1 to 4 exhibited significant improvement effects after being added to the oil-based drilling fluid system, specifically reflected in lower plastic viscosity and higher shear stress. The main reason for this phenomenon is the introduction of γ-aminopropyltriethoxysilane, which provides siloxy groups, giving the molecules a certain degree of polarity in the system. This polarity helps to form a three-dimensional network structure in the oil-based system, thereby improving the system's rheological properties. Specifically, the three-dimensional network structure not only enhances the stability of the solid phase but also optimizes the rheological properties of the oil-based system, making the drilling fluid operation more efficient and stable.

[0119] Regarding particle size evaluation, when the solid phase removers prepared in Examples 1 to 4 were added to oil-based drilling fluids, significant flocculation occurred in the white oil suspension. After treatment, the particle size increased dramatically from 4 μm to over 210 μm, indicating that the solid phase removers played an important role in promoting solid particle aggregation. Further treatment of the oil-based drilling fluid by flocculation sieving, followed by the addition of the solid phase removers prepared in Examples 1 to 4, resulted in even greater flocculation and aggregation of solid particles. After sieving, the solid particle content decreased from 54.3% without the remover to below 45.3%, demonstrating the effectiveness of the solid phase remover.

[0120] The results of the comparative experiments further verified the influence of different components on the performance of oil-based drilling fluids. Specifically:

[0121] In Comparative Example 1, without the addition of dimethyl diallyl ammonium chloride, the solid phase remover for oil-based drilling fluid failed to effectively adsorb onto the surface of harmful solid phases, thus failing to achieve its intended removal effect. The results showed no significant changes in rheology or particle size. After flocculation, the sieving effect of the solid phase was also poor, and the reduction in solid phase content was relatively limited, indicating that dimethyl diallyl ammonium chloride played a crucial role in enhancing adsorption and improving flocculation.

[0122] In Comparative Example 2, without the addition of γ-aminopropyltriethoxysilane, the solid phase scavenger still underwent adsorption on the surface of the harmful solid phase. Although it produced some flocculation, it failed to significantly improve the rheological properties of the system. The main reason for this is the lack of polar effects from the siloxy groups, which resulted in no significant change in the plastic viscosity and dynamic shear force of the oil-based system. Nevertheless, because the polymer itself contains polar groups provided by acrylamide, it still has some influence on the rheological properties of the system, manifested as a slight increase in particle size after flocculation, although the increase was smaller compared to the experimental group. This is mainly because, in the absence of siloxy groups, the surface of the harmful solid phase still retains strong oleophilicity, leading to easy redispersibility of solid particles in the oil phase and reducing the flocculation effect.

[0123] In Comparative Example 3, although dimethyl diallyl ammonium chloride was added, its dosage was too high, resulting in excessively high polymer polarity and poor solubility in oil-based drilling fluids. Therefore, the solids remover was unable to effectively adsorb onto the surface of harmful solids, further reducing its modification and flocculation effects. The results showed that after treatment, the oil phase contact angle, particle size, and solid content after sieving on the rock surface did not change significantly, further confirming the poor effectiveness of this component and demonstrating the negative impact of high concentrations of dimethyl diallyl ammonium chloride.

[0124] In summary, through comparative experiments, the addition of appropriate amounts of γ-aminopropyltriethoxysilane and dimethyldiallylammonium chloride to oil-based drilling fluid solids removers can effectively improve the rheological properties of oil-based systems, promote the flocculation and sedimentation of solid particles, thereby reducing the solid content in oil-based drilling fluids and improving their performance and operability. However, excessive amounts or deficiencies of certain key components may lead to unsatisfactory results, indicating that the proper ratio of each component is crucial to the performance of the solids remover.

[0125] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A solid phase remover for oil-based drilling fluids, characterized in that: The raw material components and their weight parts are as follows: 14-24 parts of lipophilic monomer, 2-8 parts of silicon-containing monomer, 14-30 parts of acrylamide, 4-7 parts of cationic monomer, 0.1-0.2 parts of initiator, and 1-4 parts of emulsifier.

2. The solid phase remover for oil-based drilling fluids according to claim 1, characterized in that: The lipophilic monomer is any one of hexadecyl acrylate, hexadecyl acrylate, or styrene.

3. The solid phase remover for oil-based drilling fluids according to claim 2, characterized in that: The lipophilic monomer is hexadecyl acrylate.

4. The solid phase remover for oil-based drilling fluids according to claim 1, characterized in that: The silicon-containing monomer is any one of (dimethylaminoethyl methacrylate)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, or 1,1-bis(trimethylsiloxy)-2-trimethylsilylethylene.

5. The solid phase remover for oil-based drilling fluids according to claim 1, characterized in that: The cationic monomer is a quaternary ammonium salt monomer or an imidazole monomer.

6. The solid phase remover for oil-based drilling fluids according to claim 5, characterized in that: The quaternary ammonium salt monomer is any one of vinyl quaternary ammonium salt, dimethyl diallyl ammonium chloride, or acrylamide alkyl quaternary ammonium salt monomer.

7. The solid phase remover for oil-based drilling fluids according to claim 1, characterized in that: The initiator is any one of azobisisobutyronitrile, ammonium persulfate, or potassium persulfate.

8. The solid phase remover for oil-based drilling fluids according to claim 1, characterized in that: The emulsifier is sPan80.

9. A method for preparing a solid phase remover for oil-based drilling fluid according to any one of claims 1 to 8, characterized in that: Includes the following steps: (1) Add the lipophilic monomer, cationic monomer and emulsifier to the solvent in proportion, stir until dissolved, and obtain the first reaction solution; (2) Add acrylamide and silicon-containing monomers to water and mix and stir evenly to form a second reaction solution; (3) Mix the first reaction solution and the second reaction solution to form an emulsion; (4) Heat the above reaction solution while passing nitrogen gas through it. After the temperature stabilizes, add an initiator to the emulsion to start the polymerization reaction. (5) Continue the reaction for 6 to 10 hours, and the product obtained is the target solid phase scavenger.

10. The method for preparing a solid phase remover for oil-based drilling fluid according to claim 9, characterized in that: The solvent in step (1) is white oil.

11. The method for preparing a solid phase remover for oil-based drilling fluid according to claim 9, characterized in that: The weight ratio of the lipophilic monomer, cationic monomer, emulsifier and white oil in step (1) is 14-24:4-7:1-3:

90.

12. The method for preparing a solid phase remover for oil-based drilling fluid according to claim 9, characterized in that: The weight ratio of acrylamide, silicon-containing monomer and water in step (2) is 30:2-8:45-50.

13. The method for preparing a solid phase remover for oil-based drilling fluid according to claim 9, characterized in that: In step (4), the reaction solution is heated to a temperature of 55–75°C.

14. The use of the solid phase remover for oil-based drilling fluids according to any one of claims 1-8 in oil-based drilling fluids.