Organic silicon polymer hydrophilic modified bentonite for water-based drilling fluid as well as preparation method and application of organic silicon polymer hydrophilic modified bentonite

Abstract

The invention discloses a preparation method and application of organic silicon polymer hydrophilic modified bentonite for a water-based drilling fluid, and belongs to the field of drilling fluids, the organic silicon polymer hydrophilic modified bentonite for the water-based drilling fluid comprises a reaction system and an initiator; the reaction system comprises the following components in parts by mass: 2000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of a hydrophilic vinyl organosilicon monomer, 6-8 parts of a hydrophilic anionic monomer, 1-3 parts of a cationic monomer containing a strong adsorption group and 1-2 parts of a nonionic monomer; the addition amount of the initiator is 0.05-0.1% of the total mass of the reaction system. According to the invention, the problem that bentonite in the water-based drilling fluid is easily polluted by other treating agents due to poor gel protection effect of a common filtrate loss reducing treating agent, so that the rheological property and the filtrate loss property of the drilling fluid are influenced is solved.

Description

Technical Field

[0001] The invention belongs to the field of drilling fluid, and relates to a preparation method and application of organosilicon polymer hydrophilic modified bentonite for water-based drilling fluid. Background Art

[0002] With the development of economy, the demand for energy is gradually increasing, and water-based drilling fluid technology in oil and gas industry has been widely used. Conventional water-based drilling fluid system is composed of bentonite, water and treatment agent, among which bentonite is the most important natural mineral used to adjust the rheological properties and filtration properties of water-based drilling fluid.

[0003] The dispersion state, hydration degree and fluid loss reduction effect of bentonite in water are easily affected by different treatment agents in the system. The addition of some coating agents, flocculants and inhibitors will inhibit the further hydration of bentonite in drilling fluid to a certain extent, which is not conducive to the dispersion of bentonite in drilling fluid, changes the rheological properties of bentonite slurry and deteriorates its fluid loss performance. Adding treatment agents with gel protection effect to drilling fluid, such as fluid loss reducer, can effectively reduce the impact of other treatment agents on bentonite, but the addition of fluid loss reducer and other treatment agents has a competitive adsorption relationship between clay particles. Other treatment agents often contain strong cationic adsorption groups, so the gel protection effect is easily affected by other treatment agents. Increasing the amount of fluid loss reduction and gel protection materials will increase the use cost of water-based drilling fluid, and the performance is not easy to control. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation method and application of hydrophilic modified bentonite of organosilicon polymer for water-based drilling fluid, so as to solve the problem that bentonite in water-based drilling fluid has poor protective effect of common fluid loss reducing treatment agents and is easily contaminated by other treatment agents, thus affecting the rheological and fluid loss properties of the drilling fluid.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An organosilicon polymer hydrophilic modified bentonite for water-based drilling fluid, comprising a reaction system and an initiator;

[0007] The reaction system comprises the following components in parts by mass: 2000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of hydrophilic vinyl silicone monomer, 6-8 parts of hydrophilic anionic monomer, 1-3 parts of cationic monomer containing strong adsorption groups, and 1-2 parts of nonionic monomer;

[0008] The amount of the initiator added is 0.05-0.1% of the total mass of the reaction system.

[0009] Further, the reaction system includes the following components in parts by mass: 2000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 6-8 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, 1-3 parts of cationic monomer dimethyldiallyl ammonium chloride containing strong adsorption groups, and 1-2 parts of non-ionic monomer acrylamide; the structural formula of the hydrophilic modified bentonite of the silicone polymer is as follows:

[0010]

[0011] Bentonite itself has the problems of limited dispersibility and insufficient temperature resistance. The present invention uses organic silicon materials to chemically adsorb and polymerize monomers with strong hydrophilicity and temperature resistance to prepare modified bentonite with good dispersibility and temperature resistance.

[0012] Furthermore, the reaction system includes the following components in parts by mass: 2000 parts of water, 80 parts of bentonite, 4 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropane sulfonic acid, 1 part of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, and 2 parts of non-ionic monomer acrylamide.

[0013] Furthermore, the initiator is ammonium persulfate and sodium bisulfite, and the sum of the added amounts of ammonium persulfate and sodium bisulfite is 0.05% of the total mass of the reaction system.

[0014] The present invention uses the method of organic modification of bentonite to chemically react organic matter with clay in advance, thereby changing the structure of bentonite, and significantly changing various properties of the base slurry after being added into the system.

[0015] The present invention uses OCMA-grade drilling fluid slurry bentonite with a high montmorillonite content as the main raw material for modified bentonite, wherein the main component is montmorillonite, which accounts for about 85-90% of the total soil mass. The higher the montmorillonite content, the more active hydroxyl groups on the clay surface that can react with the organosilicon monomer after hydration in the aqueous solution, which is more conducive to the chemical adsorption of the organosilicon material.

[0016] The present invention weighs bentonite and dissolves it in water, and then adds sodium carbonate to the bentonite, so as to hydrate the bentonite and convert the calcium-based bentonite therein into sodium-based bentonite;

[0017] Modification of organic silicon monomer: When bentonite is partially hydrated and has a large interlayer distance, organic silicon monomer can quickly enter the interlayer and react with the silanol groups in the interlayer to form -Si-O-Si- bonds to produce chemical adsorption. Slow addition of small amounts and multiple times can also reduce the dehydration condensation of the monomer itself. The binding force of chemical adsorption is greater than the electrostatic force, hydrogen bond, and van der Waals force. Therefore, using this chemical adsorption method as a bridge to link bentonite and the polymer composed of hydrophilic anions can enhance the stability of bentonite after full hydration, so that it will not be easily affected by other treatment agents due to physical competitive adsorption.

[0018] A large amount of anionic monomers are added, and the monomers contain strongly hydrated sulfonic acid groups, in order to improve the hydration performance of the modified bentonite and its own glue protection ability. The introduction of monomers with cationic adsorption groups and non-ionic monomers can make the incompletely reacted polymers in the aqueous solution adsorbed to the clay surface. On the one hand, it can increase the reaction efficiency with vinyl trisilanol, and on the other hand, it provides cationic and more non-ionic adsorption groups for the polymer to improve the adsorption stability of the polymer on bentonite.

[0019] The method for preparing the hydrophilic modified bentonite of organic silicon polymer for water-based drilling fluid comprises the following steps:

[0020] S1: Weighing various raw materials according to mass ratio, including water, bentonite, sodium carbonate, hydrophilic vinyl silicone monomer vinyl trisilanol, hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, cationic monomer dimethyldiallyl ammonium chloride containing strong adsorption groups, and non-ionic monomer acrylamide to form a reaction system; and also including an initiator, the amount of the initiator added is 0.05% of the total mass of the reaction system;

[0021] S2: Dissolve bentonite in water, add sodium carbonate and stir for 4-10 hours, add acetic acid to adjust the pH to 4.5-6, keep magnetic stirring, add vinyl trisilanol at room temperature, and react for 30 minutes;

[0022] S3: After step S2 reacts for 30 minutes, adjust the solution pH to 8, increase the reaction temperature to above 40°C, add 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide monomer, add initiator, and stir to react for 1.5 hours;

[0023] S4: After the reaction in step S3 is completed, the system is separated into a solid phase in a centrifuge, the soil layer in the solid phase is separated, and the solid phase is washed with ethanol for multiple times and centrifuged for 2-3 times until a single soil phase is centrifuged to obtain a wet bentonite hydrophilically modified by an organosilicon polymer;

[0024] S5: Put the wet bentonite after hydrophilic modification by the organosilicon polymer into an oven, dry it at 105±3° C. to constant weight, take it out and grind it to obtain the bentonite after hydrophilic modification by the organosilicon polymer.

[0025] Furthermore, in step S3, after step S2 reacts for 30 minutes, the pH of the solution is adjusted to 8, the reaction temperature is increased to 50° C., 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, and acrylamide monomer are added, an initiator is added, and the reaction is stirred for 1.5 hours.

[0026] Further, in step S4, after the reaction in step S3 is completed, the system is centrifuged at 8000 r·min -1 The solid phase was separated by centrifugation for 20 minutes, and the soil layer in the solid phase was separated, washed with ethanol for multiple times and centrifuged for 2-3 times until a single soil phase was centrifuged to obtain wet bentonite after hydrophilic modification by organic silicon polymer.

[0027] In step S2 of the present invention, the stirring time is 4-10h, at which time the interlayer spacing of bentonite should be 1.5-1.9nm; when the stirring time exceeds 10h, the interlayer spacing is mostly 1.7-1.9nm; when the stirring time is 24h, the interlayer spacing is mostly greater than 1.9nm, which can be regarded as fully hydrated; bentonite is dispersed in water, and the surface of clay particles after hydration carries more Si-OH, which can react with Si-OH formed after hydration of organosilicon polymer molecules, so that organosilicon is firmly adsorbed on the surface of clay particles in the form of chemical adsorption; insufficient hydration can expand the interlayer spacing of clay, which is conducive to the entry of organosilicon materials into the interlayer to produce chemical reactions, while increasing the adsorption area of ​​clay and modified materials to improve the modified yield, and at the same time better maintaining the clay layered structure, so that the basic physical and chemical properties of bentonite do not change significantly. The crystal layer of clay increases with the extension of stirring time, and different interlayer spacing affects the adsorption effect of organosilicon polymers inserted into the interlayer, and also affects the introduction of subsequent hydrophilic monomers. Therefore, the present invention limits the stirring time of bentonite.

[0028] According to the present invention, the dispersed bentonite slurry is transferred to a three-necked flask, and the magnetic stirring is maintained to control the drilling speed at 600 r / min. An excessively high drilling speed will accelerate the hydration dispersion of the bentonite, so that the interlayer distance is further expanded, which is not conducive to maintaining the layered structure of the clay, and an excessively low rotation speed is not conducive to the reaction. Acetic acid is used to adjust the pH to 4.5-6. Since the bentonite contains a large number of hydrophilic groups such as hydroxyl groups, the silanol groups will undergo a condensation reaction under acidic conditions, and the silanol condensation reaction rate is the fastest when the pH is about 4. In order to avoid a large number of self-dehydration condensation reactions of the organic silicon material, the pH of the bentonite slurry is controlled to be 4.5-6 under weakly acidic conditions, so that the silanol groups in the bentonite have dehydration activity and do not undergo strong self-dehydration condensation.

[0029] The hydrophilic organosilicon material of the present invention is vinyl trisilanol, the reaction temperature is room temperature, the pH is adjusted to acidic and the system temperature is controlled at 25°C, then 2-3 parts of hydrophilic organosilicon monomer vinyl trisilanol are slowly added dropwise to the system, and the reaction temperature is controlled at 25°C. Since the bentonite is in a partially hydrated state and has a large interlayer distance at this time, the organosilicon monomer can quickly enter the interlayer and react with the silanol groups in the interlayer to form -Si-O-Si- bonds to generate chemical adsorption. The dehydration condensation of the monomer itself can be reduced by adding a small amount of the monomer slowly for multiple times. The binding force of the chemical adsorption is greater than the electrostatic force, the hydrogen bond and the van der Waals force. Therefore, the chemical adsorption method is used as a bridge to link the bentonite and the polymer composed of the hydrophilic anion, so that the stability of the bentonite after full hydration can be enhanced and the bentonite will not be easily affected by the physical competitive adsorption of other treatment agents.

[0030] The reaction process of the organosilicon-modified bentonite and other monomers in the present invention is as follows: after the hydrophilic organosilicon material is added and fully mixed with the soil slurry for adsorption, sodium carbonate is used to adjust the pH to about 8, and the hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, the monomer dimethyldiallyl ammonium chloride with a cationic adsorption group, and the nonionic monomer acrylamide are added to the reaction system; the temperature is raised to 40-60° C. and an initiator is added; wherein a large amount of anionic monomers are added, and the monomers contain a strongly hydrated sulfonic acid group, so as to improve the hydration performance of the modified bentonite and its own glue protection ability; the introduction of the monomers with a cationic adsorption group and the nonionic monomers can make the incompletely reacted polymer in the aqueous solution adsorbed to the clay surface, which can increase the reaction efficiency with vinyl trisilanol on the one hand, and provide the polymer with cations and more nonionic adsorption groups on the other hand to improve the adsorption stability of the polymer on the bentonite.

[0031] The invention centrifuges the bentonite slurry after the modified reaction in a centrifuge, centrifuges the bentonite at 8000 r / min. -1 , separate the solid phase for 20 minutes, wash with ethanol and then centrifuge, wash and centrifuge for multiple times, put the finally separated bentonite into an oven and dry it at 105±3℃ to constant weight, take it out and grind it to obtain bentonite hydrophilically modified by silicone polymer, which can be used as drilling fluid slurry soil. It shows better dispersibility at the same soil content in water-based drilling fluid, has strong rubber protection ability, is greatly weakened by the influence of other treatment agents, improves the ζ potential of clay, and forms a thin, dense and tough mud cake with good filtration loss reduction effect.

[0032] The application of the hydrophilic modified bentonite of organic silicon polymer for water-based drilling fluid is that the hydrophilic modified bentonite of organic silicon polymer is used as drilling fluid slurry preparation soil to prepare water-based drilling fluid.

[0033] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0034] 1. In the hydrophilic modified bentonite of a water-based drilling fluid of the present invention, when the bentonite is in a partially hydrated state with a large interlayer distance, the organosilicon monomer can quickly enter the interlayer and react with the silanol groups in the interlayer to form -Si-O-Si- bonds to produce chemical adsorption. The slow addition of small amounts multiple times can also reduce the dehydration condensation of the monomer itself. The chemical adsorption method is used as a bridge to link the bentonite and the polymer composed of hydrophilic anions, which can enhance the stability of the bentonite after full hydration and prevent it from being easily affected by other treatment agents due to physical competitive adsorption;

[0035] 2. A large amount of anionic monomers are added to the hydrophilic modified bentonite of the organic silicon polymer for water-based drilling fluid of the present invention. The monomers contain a strongly hydrated sulfonic acid group, which is used to improve the hydration performance of the modified bentonite and its own glue protection ability. The introduction of monomers with cationic adsorption groups and non-ionic monomers can make the polymer that has not been completely reacted in the aqueous solution adsorbed to the clay surface, which can increase the reaction efficiency with vinyl trisilanol on the one hand, and provide the polymer with cations and more non-ionic adsorption groups on the other hand to improve the adsorption stability of the polymer on bentonite;

[0036] 3. The method for preparing hydrophilically modified bentonite by organic silicon polymer for water-based drilling fluid of the present invention obtains bentonite hydrophilically modified by organic silicon polymer, which can be used as slurry preparation soil for drilling fluid. It shows better dispersion performance under the same soil content in water-based drilling fluid, has strong glue protection ability, is greatly weakened by the influence of other treatment agents, improves the ζ potential of clay, and forms a thin, dense and tough mud cake with good filtration loss reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative work, among which:

[0038] Figure 1 It is a structural formula of hydrophilic modified bentonite of silicone polymer;

[0039] Figure 2 It is a synthetic route for hydrophilic modified bentonite by silicone polymer. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0042] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0043] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0044] The method for preparing a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid of the present invention comprises the following steps:

[0045] S1: Weigh each raw material by mass ratio, including: 22000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of hydrophilic vinyl silicone monomer, 6-8 parts of hydrophilic anionic monomer, 1-3 parts of cationic monomer containing strong adsorption groups, 1-2 parts of nonionic monomer and 0.05% of the total mass of the reaction system initiator;

[0046] S2: Dissolve bentonite in water, add sodium carbonate and stir, add acetic acid to adjust the pH to acidic, keep magnetic stirring, add vinyl silicone monomer at room temperature, and fully react for about 30 minutes;

[0047] S3: Adjust the solution pH to 8, increase the reaction temperature to above 40°C, add hydrophilic anionic monomers, cationic monomers containing strong adsorption groups, nonionic monomers, add initiators, and stir the reaction for 1.5-3h;

[0048] S4: After the reaction is completed, the system is separated into a solid phase in a centrifuge, and the soil layer in the solid phase is separated. The solid phase is washed and centrifuged with ethanol for multiple times, and the process is continued for 2-3 times until a single soil phase is centrifuged to obtain wet bentonite after hydrophilic modification by an organosilicon polymer.

[0049] S5: The wet bentonite modified by the hydrophilic modification of the organosilicon polymer is placed in an oven and dried at 105±3° C. to a constant weight, and then taken out and ground to obtain a dry sample of the bentonite modified by the hydrophilic modification of the organosilicon polymer.

[0050] The hydrophilic vinyl silicone monomer may be a silicone monomer containing a vinyl group and a hydrophilic group, or a silicone monomer containing a vinyl group that can be hydrolyzed in water to generate a hydrophilic group;

[0051] The hydrophilic anionic monomer is an anionic monomer containing a hydrophilic group with strong hydration ability, and the hydrophilic group contains one or more sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, hydroxyl groups and the like, the hydrophilicity of which is greater than or equal to that of the hydroxyl groups, such as sulfonate monomers: 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonate, ethylene sulfonate, propylene sulfonate; such as carboxylate monomers: acrylic acid, methacrylic acid, hydroxyethyl acrylic acid, itaconic acid, etc.;

[0052] The above cationic monomer is a monomer containing a strong adsorption group, and the present invention preferably uses a quaternary ammonium water-soluble cationic monomer but is not limited to a quaternary ammonium water-soluble cationic monomer;

[0053] The non-ionic monomer of the present invention is preferably acrylamide monomer but is not limited to acrylamide monomer. The non-ionic monomer can be a sub-monomer mainly including: acrylamide, N-vinyl pyrrolidone, NNDMAN, N-dimethylacrylamide, St styrene, VI vinylimidazole, vinylformamide, VP vinylpyridine, N-methyl-N-vinylacetamide, etc.

[0054] The above-mentioned pH regulator should be a weak acid or a weak base, and is not limited to acetic acid or sodium carbonate.

[0055] The initiator is one or more of a nitrogen initiator, an organic peroxide initiator, an inorganic peroxide initiator, a water-soluble redox initiator, and an oil-soluble redox initiator; wherein the azo initiator is, for example, azoisobutyronitrile and azobisisoheptanenitrile; the organic peroxide initiator is, for example, cumene hydroperoxide, tert-butyl hydroperoxide, p-menane hydroperoxide, benzoyl peroxide, dodecyl peroxide, tert-butyl peroxide, diisoacene peroxide, and tert-butyl peroxide benzoate. , diisopropyl peroxydicarbonate; inorganic peroxy initiators such as potassium persulfate, ammonium persulfate, hydrogen peroxide; water-soluble redox initiators such as: oxidants are composed of inorganic peroxy initiators and hydroperoxy initiators, and reducing agents are composed of divalent iron salts, sodium bisulfite, sodium thiosulfate, alcohols and polyamines; oil-soluble redox initiators such as: oxidants are composed of organic peroxy initiators, and reducing agents are composed of tertiary amines, ferrous cyclohexane salts, mercaptan organometallic compounds, etc. In this embodiment, the initiator used in the aqueous solution polymerization method is a water-soluble initiator, and the addition amount is 0.05-0.1wt% of the weight of the reactants.

[0056] The preferred preparation method of a water-based drilling fluid organosilicon polymer hydrophilic modified bentonite of the present invention is as follows: 80-90 parts of drilling fluid slurry bentonite is used, and 4-5 parts of sodium carbonate are added to 2000-2250 parts of water to fully dissolve and disperse them, mechanically stirred for 4-10 hours, transferred to a reaction container, the pH of the solution is adjusted to an acidic condition, stirring is maintained, and the temperature is controlled at about 25°C, 2-3 parts of hydrophilic vinyl organosilicon monomer vinyl trisilanol are added thereto, and the pH is adjusted to after sufficient reaction. 8; add 6 to 8 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, 2 to 3 parts of cationic monomer dimethyldiallyl ammonium chloride containing strong adsorption groups and 1 to 2 parts of non-ionic monomer acrylamide, add initiator, heat and stir, control the reaction temperature at 40-60°C and react for about 1.5-3h, centrifuge-wash-centrifuge-dry and grind the suspension system of the modified bentonite reaction to obtain the organosilicon polymer hydrophilic modified bentonite, the structure of the obtained organosilicon polymer hydrophilic modified bentonite is as follows Figure 1 The synthetic route is as shown in Figure 2 shown.

[0057] In some specific embodiments, the stirring time of the prehydrated bentonite is controlled to be 4 / 7 / 10 h, so that the organosilicon material can be inserted into the bentonite layer and react fully.

[0058] In some specific embodiments, the pH of the added organosilicon material is controlled to be weakly acidic 4.5 / 5.5 / 6.5, so as to control the activity of silanol groups and reduce the occurrence of self-dehydration polymerization reaction.

[0059] In some specific embodiments, the hydrophilic silicone material is slowly added dropwise to reduce the occurrence of self-condensation reaction.

[0060] In some specific embodiments, the reaction pH after adding other monomers is adjusted to a basic pH of about 8 to allow for a full reaction of the hydrophilic anionic monomer.

[0061] In some specific embodiments, a small amount of cationic monomers and nonionic monomers are introduced to enhance the adsorption performance of the monomer polymer on bentonite.

[0062] Example 1

[0063] A preferred embodiment of the present invention provides a method for preparing a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid, comprising the following steps:

[0064] Weigh the following raw materials by mass ratio: 2000 parts of water, 80 parts of bentonite, 4 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, 1 part of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, 2 parts of nonionic monomer acrylamide; 0.05% of the total mass of the system ammonium persulfate and sodium bisulfite;

[0065] Dissolve bentonite in water at room temperature and pre-hydrate and stir for 4 hours, adjust the solution pH to 4.5, add vinyl trisilanol, and stir for 30 minutes. Adjust the solution pH to 8, add 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallyl ammonium chloride, acrylamide, and initiator, heat to 40°C, and fully react for 1.5 hours. After the reaction is completed, wash and centrifuge to separate the solid modified bentonite, which is marked as sample 1.

[0066] Example 2

[0067] Based on Example 1, the present example is different from Example 1 in that: bentonite is dissolved in water at room temperature and pre-hydrated and stirred for 7 hours, the solution pH is adjusted to 5.5, vinyl trisilanol is added, and stirred for 30 minutes. The solution pH is adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide, and initiator are added, the temperature is raised to 50° C., and the reaction is fully reacted for 1.5 hours. After the reaction is completed, the solid modified bentonite is washed and centrifuged to separate, and the sample is marked as Sample 2.

[0068] Example 3

[0069] Based on Example 1, the present example is different from Example 1 in that: bentonite is dissolved in water at room temperature and pre-hydrated and stirred for 10 hours, the solution pH is adjusted to 6.5, vinyl trisilanol is added, and stirred for 30 minutes. The solution pH is adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallyl ammonium chloride, acrylamide, and initiator are added, the temperature is raised to 60° C., and the reaction is fully reacted for 1.5 hours. After the reaction is completed, the solid modified bentonite is washed and centrifuged to separate, and the sample is marked as Sample 3.

[0070] Example 4

[0071] The preparation method of this embodiment is as follows: weigh the following raw materials by mass ratio: 2000 parts of water, 80 parts of bentonite, 4 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, 2 parts of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, 2 parts of nonionic monomer acrylamide; 0.05% of ammonium persulfate and sodium bisulfite in the total mass of the system;

[0072] Bentonite was dissolved in water at room temperature and pre-hydrated and stirred for 7 hours, the solution pH was adjusted to 5.5, vinyl trisilanol was added, and stirred for 30 minutes. The solution pH was adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide, and initiator were added, the temperature was raised to 50°C, and the reaction was fully carried out for 1.5 hours. After the reaction was completed, the solid modified bentonite was washed and centrifuged to separate, and the sample was marked as sample 4.

[0073] Example 5

[0074] The preparation method of this embodiment is as follows: weigh the following raw materials by mass ratio: 2000 parts of water, 80 parts of bentonite, 4 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, 3 parts of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, 2 parts of nonionic monomer acrylamide; 0.05% of ammonium persulfate and sodium bisulfite in the total mass of the system;

[0075] Bentonite was dissolved in water at room temperature and pre-hydrated and stirred for 7 hours, the solution pH was adjusted to 5.5, vinyl trisilanol was added, and stirred for 30 minutes. The solution pH was adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide, and initiator were added, the temperature was raised to 50°C, and the reaction was fully reacted for 1.5 hours. After the reaction was completed, the solid modified bentonite was washed and centrifuged to separate, and the sample was marked as sample 5.

[0076] Example 6

[0077] Based on Example 4, this example is different from Example 4 in that the following raw materials are weighed in parts by mass: 2250 parts of water, 90 parts of bentonite, 5 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 8 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropane sulfonic acid, 3 parts of cationic monomer dimethyldiallyl ammonium chloride containing strong adsorption groups, 2 parts of nonionic monomer acrylamide; 0.05% of ammonium persulfate and sodium bisulfite of the total mass of the system;

[0078] Bentonite was dissolved in water at room temperature and pre-hydrated and stirred for 7 hours, the solution pH was adjusted to 5.5, vinyl trisilanol was added, and stirred for 30 minutes. The solution pH was adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide, and initiator were added, the temperature was raised to 50°C, and the reaction was fully reacted for 1.5 hours. After the reaction was completed, the solid modified bentonite was washed and centrifuged to separate, and the sample was marked as sample 6.

[0079] Example 7

[0080] Based on Example 4, this example is different from Example 4 in that the following raw materials are weighed in parts by mass: 2125 parts of water, 85 parts of bentonite, 4.5 parts of sodium carbonate, 2.5 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropane sulfonic acid, 2.5 parts of cationic monomer dimethyldiallyl ammonium chloride containing strong adsorption groups, 2 parts of nonionic monomer acrylamide; 0.05% of ammonium persulfate and sodium bisulfite of the total mass of the system;

[0081] Bentonite was dissolved in water at room temperature and pre-hydrated and stirred for 7 hours, the pH of the solution was adjusted to 5.5, vinyl trisilanol was added, and stirred for 30 minutes. The pH of the solution was adjusted to 8, 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide, and initiator were added, the temperature was raised to 50°C, and the reaction was fully reacted for 1.5 hours. After the reaction was completed, the solid modified bentonite was washed and centrifuged to separate, and the sample was marked as sample 7.

[0082] Test Example 1

[0083] The modified bentonite was prepared into a base slurry at 4% of the same addition system and hydrated for 24 hours. The rheological properties of the base slurries prepared with different samples were measured by a six-speed rotary viscometer. The results are shown in Table 1.

[0084] The method for preparing the base slurry of 4% according to the same addition system is as follows: weigh 16 parts of modified bentonite and dissolve them in 384 parts of water, stir at a low speed for 20 minutes and then stir at a high speed for 10 minutes to prepare a base slurry with a mass fraction of 4%.

[0085] Table 1 Rheological properties test results of sample configuration slurry

[0086] Group Apparent viscosityAV / mPa·s Plastic viscosity PV / mPa·s Dynamic shear force YP / Pa blank 10 5 5 Sample 1 21 13 8 Sample 2 34 20 14 Sample 3 30 19 11 Sample 4 37 23 14 Sample 5 34 21 13 Sample 6 28 15 13 Sample 7 33 23 10

[0087] It can be seen from Table 1 that the modified bentonites described in the present invention all have the effect of promoting bentonite hydration and slurrying, and sample 4 shows the best slurrying performance. Therefore, the preparation method of sample 4 (Example 4) is further used to evaluate the samples.

[0088] Test Example 2

[0089] According to the preparation method described in Example 4, an organosilicon polymer hydrophilic modified bentonite was obtained, and the rheological properties and filtration loss properties of the drilling fluid prepared with the organosilicon polymer hydrophilic modified bentonite were evaluated:

[0090] Test methods and test conditions: using ZNN-D6B six-speed rotary viscometer, ZNS-5A API medium-pressure fluid loss meter, GGS42-2A high-temperature and high-pressure fluid loss meter, and using ZB / TE13004-90: drilling fluid test procedure;

[0091] The bentonite hydrated slurry and the organosilicon polymer hydrophilic modified bentonite slurry with mass fractions of 2% to 8% were prepared with distilled water, and the rheological and filtration properties were tested at room temperature. The bentonite slurry samples with mass fractions of 2%, 4%, 6%, and 8% were marked as samples 1-4, and the organosilicon polymer hydrophilic modified bentonite slurry samples with mass fractions of 2%, 4%, 6%, and 8% were marked as samples 5-8. The test results are shown in Table 2.

[0092] Table 2 Rheological and filtration performance test results

[0093]

[0094]

[0095] As shown in Table 2, the performance of the hydrophilic bentonite-based slurry modified by the organosilicon polymer of the present invention is significantly better than that of the common hydrated bentonite-based slurry of the same proportion.

[0096] Test Example 3

[0097] According to the preparation method described in Example 4, a hydrophilic modified bentonite of an organosilicon polymer was obtained, and an anti-treatment agent pollution experiment of a drilling fluid prepared with the hydrophilic modified bentonite of an organosilicon polymer was conducted;

[0098] Test method and test conditions: using ZNN-D6B six-speed rotary viscometer, ZNS-5A API medium-pressure water loss meter, GGS42-2A high-temperature and high-pressure water loss meter, and using ZB / TE13004-90: drilling fluid test procedure

[0099] Distilled water was used to prepare 4% bentonite hydrated base slurry and 4% organosilicon polymer hydrophilic modified bentonite base slurry. 1% inhibitor and flocculant were added to the base slurry and the rheological and filtration loss properties were tested under the same test conditions. The smaller the change in rheological and filtration loss properties, the better the stability of the bentonite slurry. 4% bentonite base slurry, 4% bentonite base slurry + 0.5% inhibitor, 4% base slurry + 0.5% flocculant were marked as samples 1, 2, and 3, respectively. 4% organosilicon polymer hydrophilic modified bentonite base slurry, 4% organosilicon polymer hydrophilic modified bentonite base slurry + 0.5% inhibitor, 4% organosilicon polymer hydrophilic modified bentonite base slurry + 0.5% flocculant were marked as samples 4, 5, and 6, respectively. The test results are shown in Table 3.

[0100] Table 3 Anti-treatment agent pollution test results

[0101] Group Apparent viscosityAV / mPa·s Plastic viscosity PV / mPa·s Dynamic shear force YP / Pa API medium pressure loss / ml 1 9.5 6 3.5 20 2 25 1 24 8 3 2.5 1.5 1 48 4 37 23 14 6 5 39 21 18 6 6 28 19 9 10

[0102] Test Example 4

[0103] According to the preparation method described in Example 4, a hydrophilic modified bentonite of an organosilicon polymer was obtained, and the performance was compared with that of a commonly used polymer fluid loss reducer;

[0104] Test methods and test conditions: using ZNN-D6B six-speed rotary viscometer, ZNS-5A API medium-pressure fluid loss meter, GGS42-2A high-temperature and high-pressure fluid loss meter, and using ZB / TE13004-90: drilling fluid test procedure;

[0105] Distilled water was used to prepare 4% bentonite hydrated base slurry, bentonite hydrated base slurry + fluid loss reducer CMC-LV (the content was about 0.5% of the polymer equivalent mass concentration in the organosilicon polymer hydrophilic modified bentonite), and organosilicon polymer hydrophilic modified bentonite base slurry. Under the same test conditions, the rheological and fluid loss properties were compared, and the rheological and fluid loss properties after adding inhibitors and flocculants were also compared. 4% bentonite-based slurry, 4% bentonite-based slurry + 0.5% inhibitor, and 4% base slurry + 0.5% flocculant were marked as samples 1, 2, and 3, respectively; bentonite-hydrated base slurry + 0.5% fluid loss reducer CMC-LV, bentonite-hydrated base slurry + 0.5% fluid loss reducer CMC-LV + 0.5% inhibitor, and bentonite-hydrated base slurry + 0.5% fluid loss reducer CMC-LV + 0.5% flocculant were marked as samples 4, 5, and 6, respectively; 4% organosilicon polymer hydrophilic modified bentonite-based slurry, 4% organosilicon polymer hydrophilic modified bentonite-based slurry + 0.5% inhibitor, and 4% organosilicon polymer hydrophilic modified bentonite-based slurry + 0.5% flocculant were marked as samples 7, 8, and 9, respectively; the test results are shown in Table 4.

[0106] Table 4 Performance comparison test results of the present invention and conventional polymer fluid loss reducers

[0107] Group Apparent viscosityAV / mPa·s Plastic viscosity PV / mPa·s Dynamic shear force YP / Pa API medium pressure loss / ml 1 9.5 6 3.5 20 2 25 1 24 8 3 2.5 1.5 1 48 4 31 23 8 6 5 48 32 16 5 6 13 10 3 18 7 37 23 14 6 8 39 21 18 6 9 35 22 13 7

[0108] The performance of the hydrophilic modified bentonite of the organosilicon polymer of the present invention is compared with that of a commonly used polymer fluid loss reducer. The performance of the hydrophilic modified bentonite of the organosilicon polymer of the present invention is better than that of the commonly used polymer fluid loss reducer.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. The hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 1, characterized in that: Including reaction system and initiator; The reaction system comprises the following components in parts by mass: 2000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of hydrophilic vinyl silicone monomer, 6-8 parts of hydrophilic anionic monomer, 1-3 parts of cationic monomer containing strong adsorption groups, and 1-2 parts of nonionic monomer; The amount of the initiator added is 0.05-0.1% of the total mass of the reaction system.

2. The hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 1, characterized in that: The reaction system comprises the following components in parts by mass: 2000-2250 parts of water, 80-90 parts of bentonite, 4-5 parts of sodium carbonate, 2-3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 6-8 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropane sulfonic acid, 1-3 parts of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, and 1-2 parts of nonionic monomer acrylamide.

3. The hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 2, characterized in that: The reaction system comprises the following components in parts by mass: 2000 parts of water, 80 parts of bentonite, 4 parts of sodium carbonate, 3 parts of hydrophilic vinyl silicone monomer vinyl trisilanol, 7 parts of hydrophilic anionic monomer 2-acrylamide-2-methylpropane sulfonic acid, 2 parts of cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, and 2 parts of nonionic monomer acrylamide.

4. The hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 2, characterized in that: The structural formula of the hydrophilic modified bentonite of silicone polymer is as follows:

5. The hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 1, characterized in that: The initiators are ammonium persulfate and sodium bisulfite, and the sum of the added amounts of ammonium persulfate and sodium bisulfite is 0.05% of the total mass of the reaction system.

6. A method for preparing a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Weighing various raw materials according to mass ratio, including water, bentonite, sodium carbonate, hydrophilic vinyl silicone monomer vinyl trisilanol, hydrophilic anionic monomer 2-acrylamide-2-methylpropanesulfonic acid, cationic monomer dimethyldiallylammonium chloride containing strong adsorption groups, and non-ionic monomer acrylamide to form a reaction system; and also including an initiator, wherein the amount of the initiator added is 0.05-0.1% of the total mass of the reaction system; S2: Dissolve bentonite in water, add sodium carbonate and stir for 4-10 hours, add acetic acid to adjust the pH to 4.5-6, keep magnetic stirring, add vinyl trisilanol at room temperature, and react for 30 minutes; S3: After step S2 reacts for 30 minutes, adjust the solution pH to 8, increase the reaction temperature to above 40°C, add 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide monomer, add initiator, maintain magnetic stirring, increase the speed to 1000-1200 r·min-1, and fully react for 1.5h-3h; S4: After the reaction in step S3 is completed, the system is separated into a solid phase in a centrifuge, the soil layer in the solid phase is separated, and the solid phase is washed with ethanol for multiple times and centrifuged for 2-3 times until a single soil phase is centrifuged to obtain a wet bentonite hydrophilically modified by an organosilicon polymer; S5: Put the wet bentonite after hydrophilic modification by the organosilicon polymer into an oven, dry it at 105±3° C. to constant weight, take it out and grind it to obtain the bentonite after hydrophilic modification by the organosilicon polymer.

7. The method for preparing a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 6, characterized in that: In step S3, after step S2 reacts for 30 minutes, the pH of the solution is adjusted to 8, the reaction temperature is increased to 50° C., 2-acrylamide-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride, acrylamide monomer, and an initiator are added, and the reaction is stirred for 1.5 hours.

8. The method for preparing a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to claim 6, characterized in that: In step S4, after the reaction in step S3 is completed, the system is centrifuged at 8000 r / min. -1 The solid phase was separated by centrifugation for 20 minutes, and the soil layer in the solid phase was separated, washed with ethanol for multiple times and centrifuged for 2-3 times until a single soil phase was centrifuged to obtain wet bentonite after hydrophilic modification by organic silicon polymer.

9. The use of a hydrophilic modified bentonite of a silicone polymer for water-based drilling fluid according to any one of claims 1 to 5, characterized in that: The organosilicon polymer hydrophilic modified bentonite is used as drilling fluid slurry preparation soil to prepare water-based drilling fluid.

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