A water-based drilling fluid inhibitor, a water-based drilling fluid and their applications

Abstract

The present invention discloses a water-based drilling fluid inhibitor, a water-based drilling fluid and their applications, belonging to the technical field of drilling fluids. The water-based drilling fluid inhibitor is prepared by reacting 4,4'-diaminodiphenyl ether with epichlorohydrin to form a substitution product, then reacting with 10-aminodecanoic acid to form a hydroxylamine compound, and finally reacting with N,N-bis(3-aminopropyl)dodecylamine; the water-based drilling fluid comprises the following components in parts by weight: deionized water: 100 parts, inhibitor: 2-4 parts, bentonite: 5-10 parts, plugging agent: 1-3 parts, lubricant: 2-8 parts, filtration reducer: 1-4 parts, barite powder: 10-40 parts, sodium hydroxide: 0.5-1 part. The water-based drilling fluid prepared by the present invention can be applied to inhibit the hydration swelling of shale and has good lubricating performance.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling fluids, and particularly relates to a water-based drilling fluid inhibitor, a water-based drilling fluid, and their applications. Background Art

[0002] In oil and gas exploration and development, shale, as one of the important characteristic geological formations, its properties are crucial for the smooth progress of drilling. Shale often contains rich clay minerals, which are prone to swelling and dispersion when encountering water, and then destroy the wellbore stability. The economic losses caused by wellbore instability-induced accidents such as hole shrinkage, hole enlargement, stuck pipe, and even well collapse amount to billions of dollars every year. Maintaining wellbore stability is the prerequisite for achieving safe, fast, and high-quality drilling, and it is also the primary challenge in the research and development of drilling fluids. In addition, with the decreasing of shallow oil reserves, the drilling proportion of complex process wells such as extended reach horizontal wells, directional wells, cluster wells, and ultra-deep wells is increasing continuously. By adding lubricants to water-based drilling fluids, the lubricating performance of the system can be significantly improved. Lubricant molecules can adsorb between the drill string and the wellbore, and between the drill string and the casing, greatly reducing friction, torque, and drag.

[0003] Chinese Patent No. CN104151491A discloses a coating inhibitor for drilling fluids and its preparation method. The preparation method includes: mixing water and polymer monomers evenly, adjusting the pH of the mixture to 6-10 with an alkali solution; adding solvent oil and emulsifier and stirring evenly; adding an initiator for polymerization to form a coating inhibitor for drilling fluids. The coating inhibitor for drilling fluids prepared by this invention has good stability and solubility, but its inhibition performance is poor. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a water-based drilling fluid inhibitor, a water-based drilling fluid, and their applications.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0006] A water-based drilling fluid inhibitor is prepared by the following method:

[0007] S1: Mix anhydrous ethanol and 4,4'-diaminodiphenyl ether evenly, heat up to 60-75 °C, dropwise add epichlorohydrin, and reflux for 45-50 h to obtain a substitution product. The reaction equation is shown as follows:

[0008]

[0009] S2: Under nitrogen protection, mix DMF, triethylamine, and the substitution product evenly, add 10-aminodecanoic acid, heat up to 70-90 °C, and react for 4-6 h to obtain a hydroxylamine compound. The reaction equation is shown as follows:

[0010]

[0011] S3: Under nitrogen protection, stir and mix N-methylpyrrolidone, pyridine, triphenyl phosphite, and the hydroxylamine compound evenly, add N,N-bis(3-aminopropyl)dodecylamine, heat up to 100 - 150 °C, and react for 10 - 15 h. The carboxyl group in the hydroxylamine compound reacts with the amino group in N,N-bis(3-aminopropyl)dodecylamine to form an amide bond, obtaining an inhibitor with a hyperbranched structure.

[0012] In step S1, the molar ratio of the feed of 4,4'-diaminodiphenyl ether to epichlorohydrin is 1:(4.2 - 4.5).

[0013] In step S2, the molar ratio of the feed of the substitution product, 10-aminodecanoic acid, and triethylamine is 1:(4 - 4.2):(4.5 - 5).

[0014] In step S3, the molar ratio of the feed of pyridine, triphenyl phosphite, the hydroxylamine compound, and N,N-bis(3-aminopropyl)dodecylamine is (8 - 10):(4 - 5):2:(1.1 - 1.4).

[0015] An aqueous drilling fluid containing the aqueous drilling fluid inhibitor as described above, comprising the following components in parts by weight:

[0016] Deionized water: 100 parts, inhibitor: 2 - 4 parts, bentonite: 5 - 10 parts, plugging agent: 1 - 3 parts, lubricant: 2 - 8 parts, filtration reducer: 1 - 4 parts, barite powder: 10 - 40 parts, sodium hydroxide: 0.5 - 1 part.

[0017] The plugging agent is one of sulfonated asphalt and nano-polyester.

[0018] The lubricant is prepared by the following method:

[0019] M1: Stir and mix acetone, 11-heneicosanol, maleic anhydride, and anhydrous sodium acetate evenly, heat up to reflux, and react to obtain an esterification product; the reaction equation is shown as follows:

[0020]

[0021] M2: Stir and mix methanol, diethylenetriamine, and the esterification product evenly, heat up to reflux and react to obtain the lubricant, and the reaction equation is shown as follows:

[0022]

[0023] The filtration reducer is one of sodium carboxymethylcellulose and sulfonated methylphenolic resin.

[0024] The application of the above water-based drilling fluid in inhibiting shale hydration swelling.

[0025] Due to the above technical solutions, the beneficial effects of the present invention include:

[0026] (1) The present invention synthesizes an inhibitor with a hyperbranched structure, which has a good inhibitory effect on shale hydration swelling.

[0027] (2) The present invention synthesizes a new type of lubricant, which can effectively reduce the wear between friction contact surfaces after being used in the water-based drilling fluid. Detailed implementation manners

[0028] The following further illustrates with examples, but the present invention is not limited to these examples.

[0029] Example 1 Preparation of the inhibitor:

[0030] S1: Add 1000 ml of absolute ethanol and 1 mol of 4,4'-diaminodiphenyl ether into the reaction kettle in sequence, stir and mix evenly, heat up to 75 °C, dropwise add 4.2 mol of epichlorohydrin, finish dropping in 1 h, reflux and react for 45 h, add 450 g of potassium carbonate and stir for 30 min, cool to room temperature, carry out reduced pressure distillation at 50 °C for 2 h, add 800 ml of ether and stir to dissolve, extract with deionized water for 3 times (500 ml each time), carry out reduced pressure distillation at 40 °C for 3 h to obtain the substituted product;

[0031] S2: Under nitrogen protection, add 2000 ml of DMF, 4.5 mol of triethylamine and 1 mol of the substituted product into the reaction kettle in sequence, stir and mix evenly, add 4 mol of 10-aminodecanoic acid, heat up to 70 °C, react for 6 h, cool to room temperature, add 800 ml of deionized water, stir to precipitate, filter to obtain a solid, wash with 800 ml of deionized water, and vacuum dry at 70 °C for 24 h to obtain the hydroxylamine compound, and its nuclear magnetic resonance hydrogen spectrum data are as follows: 11H NMR (300 MHz, DMSO-d6) δ 11.48 (s, 4H), 6.94 - 6.79 (m, 8H), 5.40 (tt, J = 6.9, 4.8 Hz, 4H), 5.04 (d, J = 5.8 Hz, 4H), 3.96 (h, J = 5.1 Hz, 4H), 3.41 (dd, J = 13.0, 5.3 Hz, 4H), 3.20 - 3.09 (m, 4H), 2.85 (ddd, J = 13.0, 6.9, 4.9 Hz, 4H), 2.78 - 2.53 (m, 12H), 2.26 (t, J = 8.9 Hz, 8H), 1.60 - 1.37 (m, 16H), 1.37 - 1.20 (m, 40H);

[0032] S3: Under nitrogen protection, 2000 ml of N-methylpyrrolidone, 8 mol of pyridine, 4 mol of triphenyl phosphite, and 2 mol of hydroxylamine compound were successively added to the reaction kettle, stirred and mixed evenly, 1.1 mol of N,N-bis(3-aminopropyl)dodecylamine was added, the temperature was raised to 100 °C, and the reaction was carried out for 15 h. After cooling to room temperature, 1200 ml of deionized water was added to precipitate solids, filtered, washed with 500 ml of deionized water, and dried in vacuo at 70 °C for 24 h to obtain the inhibitor.

[0033] Example 2 Preparation of the inhibitor:

[0034] S1: 1000 ml of absolute ethanol and 1 mol of 4,4'-diaminodiphenyl ether were successively added to the reaction kettle, stirred and mixed evenly, the temperature was raised to 70 °C, 4.4 mol of epichlorohydrin was added dropwise, and the addition was completed in 1 h. The mixture was refluxed for 48 h, 450 g of potassium carbonate was added and stirred for 30 min. After cooling to room temperature, it was distilled under reduced pressure at 50 °C for 2 h. 800 ml of ether was added and stirred to dissolve, and it was extracted with deionized water 3 times (500 ml each time), and distilled under reduced pressure at 40 °C for 3 h to obtain the substituted product;

[0035] S2: Under nitrogen protection, 2000 ml of DMF, 4.8 mol of triethylamine, and 1 mol of the substituted product were successively added to the reaction kettle, stirred and mixed evenly, 4.1 mol of 10-aminodecanoic acid was added, the temperature was raised to 80 °C, and the reaction was carried out for 5 h. After cooling to room temperature, 800 ml of deionized water was added, stirred to precipitate, filtered to obtain solids, washed with 800 ml of deionized water, and dried in vacuo at 70 °C for 24 h to obtain the hydroxylamine compound;

[0036] S3: Under nitrogen protection, 2000 ml of N-methylpyrrolidone, 9 mol of pyridine, 4.5 mol of triphenyl phosphite, and 2 mol of hydroxylamine compound were successively added to the reaction kettle, stirred and mixed evenly, 1.3 mol of N,N-bis(3-aminopropyl)dodecylamine was added, the temperature was raised to 120 °C, reacted for 14 h, cooled to room temperature, 1200 ml of deionized water was added to precipitate solids, filtered, washed with 500 ml of deionized water, and vacuum dried at 70 °C for 24 h to obtain the inhibitor.

[0037] Example 3 Preparation of inhibitor:

[0038] S1: 1000 ml of anhydrous ethanol and 1 mol of 4,4'-diaminodiphenyl ether were successively added to the reaction kettle, stirred and mixed evenly, the temperature was raised to 60 °C, 4.5 mol of epichlorohydrin was added dropwise, and the addition was completed in 1 h. The mixture was refluxed for 50 h, 450 g of potassium carbonate was added and stirred for 30 min, cooled to room temperature, distilled under reduced pressure at 50 °C for 2 h, 800 ml of ether was added and stirred to dissolve, and extracted with deionized water 3 times (500 ml each time), and distilled under reduced pressure at 40 °C for 3 h to obtain the substituted product;

[0039] S2: Under nitrogen protection, 2000 ml of DMF, 5 mol of triethylamine, and 1 mol of substituted product were successively added to the reaction kettle, stirred and mixed evenly, 4.2 mol of 10-aminodecanoic acid was added, the temperature was raised to 90 °C, reacted for 4 h, cooled to room temperature, 800 ml of deionized water was added, stirred to precipitate, filtered to obtain solids, washed with 800 ml of deionized water, and vacuum dried at 70 °C for 24 h to obtain the hydroxylamine compound;

[0040] S3: Under nitrogen protection, 2000 ml of N-methylpyrrolidone, 10 mol of pyridine, 5 mol of triphenyl phosphite, and 2 mol of hydroxylamine compound were successively added to the reaction kettle, stirred and mixed evenly, 1.4 mol of N,N-bis(3-aminopropyl)dodecylamine was added, the temperature was raised to 150 °C, reacted for 10 h, cooled to room temperature, 1500 ml of deionized water was added to precipitate solids, filtered, washed with 500 ml of deionized water, and vacuum dried at 70 °C for 24 h to obtain the inhibitor.

[0041] Example 4 Preparation of lubricant:

[0042] M1: 1500 ml of acetone, 2.1 mol of 11-heneicosanol, 1 mol of maleic anhydride, and 0.1 mol of anhydrous sodium acetate were successively added to the reaction kettle, stirred and mixed evenly, the temperature was raised to reflux, reacted for 5 h, distilled under reduced pressure at 40 °C for 2 h, washed with deionized water 3 times (500 ml each time), and vacuum dried at 60 °C for 48 h to obtain the esterification product;

[0043] M2: 500 ml of methanol and 1 mol of diethylenetriamine were added to the reaction kettle in sequence, and 800 ml of methanol solution containing 2 mol of esterification product was added dropwise. The temperature was raised to reflux, and the reaction was continued for 15 hours. The lubricant was cooled to room temperature and distilled under reduced pressure at 40°C to obtain a lubricant. Its H NMR spectrum data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 4.72 (dt, J=8.4, 5.1 Hz, 2H), 4.60 (d, J=10.0 Hz, 4H), 3.98 (d, J=8.5 Hz, 2H), 3.12 (q, J=4.9 Hz, 1H), 2.85-2.62 (m, 10H), 2.56 (d, J=7.4 Hz, 2H), 1.78-1.58 (m, 8H), 1.53-1.37 (m,16H), 1.37-1.21 (m, 120H), 0.98-0.80 (m, 24H).

[0044] Example 5 Preparation of water-based drilling fluid:

[0045] N1: weigh: deionized water: 10 kg, inhibitor (prepared in Example 1): 0.2 kg, bentonite: 0.5 kg, sulfonated asphalt: 0.1 kg, lubricant (prepared in Example 4): 0.2 kg, sodium carboxymethyl cellulose: 0.1 kg, barite powder: 1 kg, sodium hydroxide: 0.05 kg;

[0046] N2: Mix bentonite and deionized water and stir for 1 hour to form a uniform base slurry. Add inhibitor, sulfonated asphalt, lubricant, sodium carboxymethyl cellulose, and sodium hydroxide in sequence while stirring. Stir well. Add barite powder and stir for 0.5 hour to obtain a water-based drilling fluid.

[0047] Example 6 Preparation of water-based drilling fluid:

[0048] N1: weigh: deionized water: 10 kg, inhibitor (prepared in Example 2): 0.3 kg, bentonite: 0.8 kg, nano polyester: 0.2 kg, lubricant (prepared in Example 4): 0.6 kg, sulfomethyl phenolic resin: 0.3 kg, barite powder: 3 kg, sodium hydroxide: 0.08 kg;

[0049] N2: Mix bentonite and deionized water and stir for 2 hours to form a uniform base slurry. Add inhibitor, nano polyester, lubricant, sulfomethyl phenolic resin and sodium hydroxide in sequence under stirring, stir thoroughly, add barite powder and stir for 1 hour to obtain water-based drilling fluid.

[0050] Example 7 Preparation of water-based drilling fluid:

[0051] N1: Weigh: deionized water: 10 kg, inhibitor (prepared in Example 3): 0.4 kg, bentonite: 1.0 kg, nano-polyester: 0.3 kg, lubricant (prepared in Example 4): 0.8 kg, sulfomethylated phenolic resin: 0.4 kg, barite powder: 4.0 kg, sodium hydroxide: 0.1 kg;

[0052] N2: Mix bentonite and deionized water and stir for 2 h to form a uniform base slurry. While stirring, successively add the inhibitor, nano-polyester, lubricant, sulfomethylated phenolic resin, and sodium hydroxide, stir well, add barite powder and stir for 1 h to obtain an aqueous drilling fluid.

[0053] Comparative Example 1

[0054] The preparation of the aqueous drilling fluid is basically the same as that of Example 6, except that the inhibitor (prepared in Example 2) is replaced with an equal mass of hydroxylamine compound (prepared in Step S2 of Example 2).

[0055] Comparative Example 2

[0056] The preparation of the aqueous drilling fluid is basically the same as that of Example 6, except that the inhibitor (prepared in Example 2) is replaced with an equal mass of inhibitor prepared by the following method:

[0057] The preparation method of the inhibitor is basically the same as that of Example 2, except that 4,4'-diaminodiphenyl ether in Step S1 is replaced with an equimolar amount of 1,5-diaminopentane.

[0058] Comparative Example 3

[0059] The preparation of the aqueous drilling fluid is basically the same as that of Example 6, except that the inhibitor (prepared in Example 2) is replaced with an equal mass of inhibitor prepared by the following method:

[0060] The preparation method of the inhibitor is basically the same as that of Example 2, except that 4,4'-diaminodiphenyl ether in Step S1 is replaced with an equimolar amount of 4,4'-diaminodiphenylmethane.

[0061] Comparative Example 4

[0062] The preparation of the aqueous drilling fluid is basically the same as that of Example 6, except that the inhibitor (prepared in Example 2) is replaced with an equal mass of inhibitor prepared by the following method:

[0063] The preparation method of the inhibitor is basically the same as that of Example 2, except that N,N-bis(3-aminopropyl)dodecylamine in Step S3 is replaced with an equimolar amount of 1,7-diaminoheptane.

[0064] Comparative Example 5

[0065] The preparation of the water-based drilling fluid is basically the same as that of Example 6, except that the lubricant (prepared in Example 4) is replaced with an equal mass of the esterification product (prepared in Step M1 of Example 4).

[0066] Comparative Example 6

[0067] The preparation of the water-based drilling fluid is basically the same as that of Example 6, except that the lubricant (prepared in Example 4) is replaced with an equal mass of the lubricant prepared by the following method:

[0068] The preparation method of the lubricant is basically the same as that of Example 4, except that 11-heneicosanol in Step M1 is replaced with an equimolar amount of 1-undecanol.

[0069] Comparative Example 7

[0070] The preparation of the water-based drilling fluid is basically the same as that of Example 6, except that the lubricant (prepared in Example 4) is replaced with an equal mass of the lubricant prepared by the following method:

[0071] The preparation method of the lubricant is basically the same as that of Example 4, except that the addition amount of the esterification product in Step M2 is changed from 2 mol to 5 mol.

[0072] The raw materials used in the examples and comparative examples of this application are as follows: The model of bentonite is SUPBENT-LD, produced by Hangzhou Xihe Chemical Co., Ltd.; the model of sulfonated asphalt is DMFT-1, produced by Shandong Daming Fine Chemical Co., Ltd.; the model of nano-polyester is NP-1, produced by Shandong Deshunyuan Petroleum Technology Co., Ltd.; the model of sodium carboxymethyl cellulose is PAC-HV, produced by Shandong Xuanghai Chemical Co., Ltd.; the model of sulfonated methyl phenolic resin is SMP-III; the model of barite powder is BARITE 4.3, produced by Shaker (Tianjin) Petroleum Technology Service Co., Ltd.

[0073] The shale swelling rate tests were conducted on the drilling fluids prepared in Examples 5-7 and Comparative Examples 1-7: First, the shale was crushed into powder using a pulverizer and passed through a 100-mesh sieve; a filter paper was placed in the sample cell and the height was recorded; 10 g of shale powder was weighed and put into the sample cell, compressed under a pressure of 6000 psi for 5 min, the total height after compressing the shale was measured, and the height H0 of the shale was calculated; the sample cell was fixed in the slurry cup, and the drilling fluids were respectively added into the slurry cup and immediately sealed; a linear swelling rate measuring instrument was used to record the swelling height H1 at 24 h, and the swelling rate A% = (H1 - H0) / H0 × 100% was tested; the water-based drilling fluids prepared in Examples 5-7 and Comparative Examples 5-7 were tested for lubrication coefficient according to the method of SY / T6094-1994 Evaluation Procedure for Lubricants Used in Drilling Fluids (applying a pressure of 150 psi with a torque arm and maintaining a rotational speed of 60 r / min), and the experimental results were compared with the lubrication coefficient of the drilling fluid without adding lubricant to obtain the lubrication coefficient reduction rate. The test results are shown in Table 1.

[0074] Table 1 Data Sheet of Performance Tests

[0075]

[0076] From the data of Examples 5, 6, and 7 in Table 1, it can be seen that the drilling fluid prepared by the present invention has a low swelling rate and a good lubrication coefficient reduction rate, indicating that the drilling fluid prepared by the present application can effectively inhibit shale hydration swelling and reduce the wear of drill tools such as drill pipes.

[0077] The inhibitor prepared by the present invention has a hyperbranched structure, can form stronger chemical adsorption or hydrogen bond interactions through high-density functional groups, adsorb on the clay surface to form a dense physical barrier, hinder the penetration of water molecules and ions into the interlayer, and effectively reduce clay hydration swelling; by introducing a hydrophobic long chain through N,N-bis(3-aminopropyl)dodecylamine, when it adsorbs on the clay surface, the hydrophobic long chain can extend outward, converting the hydrophilic clay surface into a hydrophobic surface and effectively preventing the penetration of water molecules; the conjugated π-electron system of the benzene ring can form a strong adsorption interaction with the cations (such as Al 3+ 、Ca 2+ )on the clay particle surface through electrostatic attraction, stabilize the clay structure, and the steric hindrance of its rigid structure can effectively prevent water molecules from entering the interlayer space of the clay platelets; the oxygen atom in the ether bond (-O-) structure can form a hydrogen bond with the hydroxyl group (-OH) on the clay surface, enhance the adsorption strength of the inhibitor on the clay particle surface, and thus improve its effect of inhibiting swelling and hydration.

[0078] In the lubricant prepared by the present invention, secondary amines (-NH-) are introduced. Their strong coordination effect can effectively adsorb on the friction surface, form stable chemical bonds, enhance the adhesion of the lubricant, and thus form a dense lubricating film. At the same time, ester groups (-COO-) and hydroxyl groups (-OH) can bind to the active sites (such as hydroxyl groups and siloxane bonds) of the metal surface or clay particles through hydrogen bonding to form a dense adsorption layer. The synergistic effect of multiple functional groups forms an effective friction boundary lubricating layer with the surface of the drill tool, reducing the direct contact of the friction surface and significantly improving the lubrication performance. Long-chain alkyl groups with linear and symmetrical structures are introduced. When their molecules are arranged, they can be closely packed with the smallest steric hindrance to form a dense oil film. The oil film forms a physical isolation layer between the drill tool and the wellbore wall, reducing the direct contact area and effectively improving the lubrication performance.

[0079] In Comparative Example 5, only the ester group provides adsorption performance and cannot form a tight adsorption with the friction interface, resulting in low lubrication performance. In Comparative Example 6, the density of the long-chain alkyl groups in the lubricant used is limited, and a continuous and stable oil film layer cannot be formed on the surface to cover and protect the contact surface, so that the lubrication performance is limited. In Comparative Example 7, due to the relatively large amount of esterification products added, compared with the lubricant in Example 4, its secondary amine will also react with the double bond of the esterification product, resulting in too high a proportion of alkyl chains in the single-molecule lubricant and relatively few adsorption groups (-NH-). During the friction process, it is more likely to peel off or slip, weakening the lubrication effect.

[0080] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. However, for those of ordinary skill in the art, within the scope of the technical solution of the present invention, any equivalent changes such as slight modifications, refinements, and evolutions made using the technical content disclosed above are equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A water-based drilling fluid inhibitor, characterized in that, Prepared by the following method: S1: Stir and mix absolute ethanol and 4,4'-diaminodiphenyl ether evenly, heat up to 60 - 75 °C, dropwise add epichlorohydrin, and reflux for 45 - 50 h to obtain a substitution product, whose structural formula is: ； S2: Under nitrogen protection, stir and mix DMF, triethylamine, and the substitution product evenly, add 10-aminodecanoic acid, heat up to 70 - 90 °C, and react for 4 - 6 h to obtain a hydroxylamine compound, whose structural formula is: S3: Under nitrogen protection, stir and mix N-methylpyrrolidone, pyridine, triphenyl phosphite, and the hydroxylamine compound evenly, add N,N-bis(3-aminopropyl)dodecylamine, heat up to 100 - 150 °C, and react for 10 - 15 h to obtain an inhibitor. The molar ratio of the charged pyridine, triphenyl phosphite, hydroxylamine compound, and N,N-bis(3-aminopropyl)dodecylamine is (8 - 10):(4 - 5):2:(1.1 - 1.4).

2. The water-based drilling fluid inhibitor according to claim 1, wherein In step S1, the molar ratio of the charged 4,4'-diaminodiphenyl ether and epichlorohydrin is 1:(4.2 - 4.5).

3. The water-based drilling fluid inhibitor according to claim 1, characterized in that, In step S2, the molar ratio of the charged substitution product, 10-aminodecanoic acid, and triethylamine is 1:(4 - 4.2):(4.5 - 5).

4. A water-based drilling fluid, characterized in that, Comprising the following components in parts by weight: Deionized water: 100 parts, the water-based drilling fluid inhibitor according to any one of claims 1 - 3: 2 - 4 parts, bentonite: 5 - 10 parts, plugging agent: 1 - 3 parts, lubricant: 2 - 8 parts, filtrate reducer: 1 - 4 parts, barite powder: 10 - 40 parts, sodium hydroxide: 0.5 - 1 part.

5. The water-based drilling fluid according to claim 4, characterized in that, The plugging agent is one of sulfonated asphalt and nano-polyester.

6. The water-based drilling fluid according to claim 4, characterized in that, The lubricant is prepared by the following method: M1: Stir and mix acetone, 11-heneicosanol, maleic anhydride, and anhydrous sodium acetate evenly, heat up to reflux, and react to obtain an esterification product; M2: Stir and mix methanol, diethylenetriamine, and the esterification product evenly, heat up to reflux and react to obtain a lubricant.

7. The water-based drilling fluid according to claim 4, wherein The filtrate reducer is one of sodium carboxymethyl cellulose and sulfomethylated phenolic resin.

8. Use of a water-based drilling fluid according to any one of claims 4 - 7 in inhibiting shale hydration swelling.

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