A filter loss reducer for antarctic drilling fluid and a preparation method and application thereof

Abstract

The application provides a filter loss reducer for Antarctic drilling fluid and a preparation method and application thereof, and belongs to the technical field of Antarctic drilling. The preparation method of the filter loss reducer for Antarctic drilling fluid comprises the following steps: (1) adding a layered silicate into deionized water, stirring and hydrating to obtain a suspension; (2) adjusting the pH of the suspension obtained in the step (1) to 7.5-8.5, adding a quaternary ammonium salt solution, and performing a reaction to obtain a reaction liquid; and (3) adding an aqueous (3-(oxanylene-2-ylmethoxy)propyl)triethoxysilane solution to the reaction liquid obtained in the step (2) and performing a reaction; after the reaction is completed, centrifugation, drying and crushing are performed to obtain the filter loss reducer for Antarctic drilling fluid. The filter loss reducer can improve the technical problem that the filter loss of the drilling fluid is large in the ice layer and the ice-rock interlayer, and can improve the ultralow-temperature rheological property of the drilling fluid.

Description

TECHNICAL FIELD

[0001] The application relates to a filter loss reducer for Antarctic drilling fluid and a preparation method and application thereof, and belongs to the technical field of Antarctic drilling. BACKGROUND

[0002] The Antarctic is rich in energy resources, including oil, natural gas, and uranium. However, the super-low temperature environment and complex geological conditions in the Antarctic put high requirements on Antarctic drilling technology. Drilling fluid is an important part of drilling engineering. When drilling in the Antarctic ice layer, the warm ice layer, and the ice-rock interlayer, wellbore instability is a common downhole complex accident, which will directly lead to the failure of drilling operations. The filter loss reducer is one of the core treatment agents of the drilling fluid, which can form a thin and dense filter cake on the wellbore surface, thereby improving the wellbore stability.

[0003] At present, good results have been achieved in the development of conventional oil-based drilling fluid filter loss reducers. For example, Chinese patent document CN118620137A discloses an oil-based drilling fluid filter loss reducer. The filter loss reducer is prepared from monomers (NMAN and MAA), an initiator (ammonium persulfate), an alkene-containing long-chain alkyl lipid compound (dodecanol methacrylate), a crosslinking agent (divinylbenzene), and the like. The filter loss reducer has stable performance, strong adaptability, can meet the drilling requirements of various complex well conditions, and has good biodegradability. Chinese patent document CN118562031A discloses an oil-based drilling fluid cyclodextrin nanosponge temperature-resistant filter loss reducer. The filter loss reducer is prepared from cyclodextrin, which is environmentally friendly, easily degradable, and has strong temperature resistance. Under the catalysis of an organic base, a crosslinking polymerization reaction occurs to prepare a nanosponge crosslinked polymer filter loss reducer. The filter loss reducer can significantly reduce the filtration loss of drilling fluid under high temperature conditions, and has little effect on the rheological property of the drilling fluid. Chinese patent document CN118440674A discloses an oil-based drilling fluid long-chain oil-soluble resin filter loss reducer. The filter loss reducer is prepared from EVA resin emulsion, styrene methyl methacrylate resin, and 800-mesh calcium carbonate powder. After aging at 240 DEG C for 16 hours, the filtration loss of the drilling fluid with the filter loss reducer is kept at 6-11 mL, and the performance is good.

[0004] However, there is no report on a low-temperature-resistant drilling fluid filter loss reducer suitable for the Antarctic region. Therefore, it is urgent to develop a super-low-temperature drilling fluid filter loss reducer suitable for the Antarctic region to improve the wellbore stability and the rock-carrying performance of the drilling fluid. SUMMARY

[0005] In view of the deficiencies of the prior art, in order to solve the technical blank of the low-temperature resistant drilling fluid filtrate reducer in the Antarctic region, the application provides a filtrate reducer for Antarctic drilling fluid and a preparation method and application thereof.The filtrate reducer can improve the large filtration loss problem of the drilling fluid in the Antarctic ice layer and ice-rock interlayer, and improve the ultralow-temperature rheological property of the drilling fluid.

[0006] The technical scheme of the application is as follows:

[0007] A preparation method of a filtrate reducer for Antarctic drilling fluid, comprising the following steps:

[0008] (1) adding a layered silicate into deionized water, stirring and hydrating to obtain a suspension;

[0009] (2) adjusting the pH of the suspension obtained in step (1) to 7.5-8.5, adding a quaternary ammonium salt solution, and reacting to obtain a reaction solution;

[0010] (3) adding an aqueous (3-(oxirane-2-ylmethoxy)propyl)triethoxysilane solution to the reaction solution obtained in step (2) and reacting; after the reaction is completed, centrifugation, drying and crushing are performed to obtain the filtrate reducer for Antarctic drilling fluid.

[0011] According to the application, preferably, the layered silicate in step (1) is magnesium lithium silicate or montmorillonite.

[0012] According to the application, preferably, the temperature of the stirring and hydrating in step (1) is room temperature, and the time of the stirring and hydrating is 1-2 h.

[0013] According to the application, preferably, the mass concentration of the suspension in step (1) is 3-5 wt%.

[0014] According to the application, preferably, in step (2), a mass fraction of 20-30% of the aqueous sodium hydroxide solution is used to adjust the pH of the suspension to 7.5-8.5.

[0015] According to the application, preferably, the quaternary ammonium salt in step (2) is methacryloyloxyethyl trimethyl ammonium chloride or (3-acrylamidopropyl) trimethyl ammonium chloride; and the mass concentration of the quaternary ammonium salt solution is 2-3 wt%.

[0016] According to the application, preferably, the mass ratio of the quaternary ammonium salt in the quaternary ammonium salt solution to the layered silicate in the suspension in step (2) is 1:2.2-3.5.

[0017] According to the application, preferably, the temperature of the reaction in step (2) is 70-80 DEG C; and the time of the reaction is 3-5 h.

[0018] Preferably, the mass concentration of the aqueous (3-(oxan-2-ylmethoxy)propyl)triethoxysilane solution in step (3) is 1.5-2.5 wt%.

[0019] Preferably, the mass ratio of (3-(oxan-2-ylmethoxy)propyl)triethoxysilane in the aqueous (3-(oxan-2-ylmethoxy)propyl)triethoxysilane solution to the layered silicate in the suspension in step (3) is 1:7-10.5.

[0020] Preferably, the temperature of the reaction in step (3) is 80-90 DEG C, and the reaction time is 1-3 h.

[0021] Preferably, the drying in step (3) is vacuum drying at 50-60 DEG C for 10-15 h.

[0022] The application provides a filter loss reducer for Antarctic drilling fluid, which is prepared by the preparation method.

[0023] According to the application, the filter loss reducer for Antarctic drilling fluid is applied to Antarctic drilling fluid, wherein the Antarctic drilling fluid comprises base oil, a surfactant and the filter loss reducer for Antarctic drilling fluid, the base oil is obtained by mixing No. 4 aviation kerosene and No. 5 white oil at a volume ratio of 8:2, the surfactant is sodium dodecyl benzene sulfonate, the mass of the surfactant is 2-4% of the mass of the base oil, and the mass of the filter loss reducer for Antarctic drilling fluid is 1-3% of the mass of the base oil; the Antarctic drilling fluid is used in the drilling process of Antarctic ice layers and ice-rock interbeds.

[0024] In the application, room temperature has the known meaning, that is, 25±5 DEG C.

[0025] The technical features and beneficial effects of the application are as follows.

[0026] 1. The preparation method is simple, and the obtained filter loss reducer is safe, environmentally friendly and free of irritating odor.

[0027] 2. The monomers used to prepare the filter loss reducer are optimally combined in specific types and specific proportions to achieve the excellent effects of the application.

[0028] 3. The filter loss reducer is prepared from a quaternary ammonium salt, (3-(oxan-2-ylmethoxy)propyl)triethoxysilane and a layered silicate. First, the quaternary ammonium salt intercalates into the interlayer of the silicate to exchange cations, thereby increasing the interlayer distance. Meanwhile, the lipophilic long chain of the quaternary ammonium salt greatly improves the lipophilicity of the silicate. In addition, (3-(oxan-2-ylmethoxy)propyl)triethoxysilane forms a covalent bond with the silicate sheet, further improving the dispersibility of the filter loss reducer in the drilling fluid.

[0029] 4、The filtrate reducer of the present application is easy to peel into nanoscale lamellas in oil phase, and has excellent low-temperature colloidal dispersibility in drilling fluid; meanwhile, the polar groups thereof form a network structure through interactions such as hydrogen bond and electrostatic attraction. This significantly improves the compactness of filter cake, and finally reduces the filtration loss of drilling fluid.

[0030] 5、The mass ratio of the quaternary ammonium salt to the layered silicate in the present application needs to be appropriate. If the ratio is too high, the excess quaternary ammonium salt will affect the arrangement of the modified silicate molecules between the layers, and further affect the thickness and size of the lamellas of the filtrate reducer. If the ratio is too low, the interlayer spacing of the modified silicate will be small, which finally affects the peeling degree of the filtrate reducer in the drilling fluid, and further affects the filtrate reduction effect thereof in the drilling fluid. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The infrared spectrum of the filtrate reducer for Antarctic drilling fluid prepared in Example 1.

[0032] Figure 2 The transmission electron microscope image of the filtrate reducer for Antarctic drilling fluid prepared in Example 1. DETAILED DESCRIPTION

[0033] The present application will be further described below through specific examples, but is not limited thereto.

[0034] The experimental methods described in the examples are all conventional methods unless otherwise specified; the reagents and materials used are all available from commercial channels unless otherwise specified.

[0035] Example 1

[0036] A preparation method of a filtrate reducer for Antarctic drilling fluid, comprising the following steps:

[0037] (1) 12 g of magnesium lithium silicate is added to 288 g of deionized water, and stirred to hydrate at room temperature for 1.5 h to obtain a suspension with a mass concentration of 4 wt%;

[0038] (2) 5 g of (3-acrylamidopropyl) trimethylammonium chloride is added to 195 g of deionized water to obtain a quaternary ammonium salt solution with a mass concentration of 2.5 wt%;

[0039] (3) 1.6 g of (3-(oxirane-2-ylmethoxy)propyl) triethoxysilane (CAS No.: 2602-34-8) is added to 78.4 g of deionized water to obtain a (3-(oxirane-2-ylmethoxy)propyl) triethoxysilane aqueous solution with a mass concentration of 2 wt%;

[0040] (4) The pH of the suspension obtained in step (1) was adjusted to 8 using a 30% sodium hydroxide aqueous solution, and the quaternary ammonium salt solution obtained in step (2) was added, and the reaction was carried out at 70°C for 4h to obtain a reaction solution;

[0041] (5) The reaction solution obtained in step (4) was added with the (3-(oxirane-2-ylmethoxy)propyl)triethoxysilane aqueous solution obtained in step (3), and the reaction was carried out at 80°C for 2h; after the reaction was completed, the reaction solution was centrifuged at 10000rpm for 10 minutes, and the obtained precipitate was dried at 60°C under vacuum for 12 hours, then crushed and finally passed through a 200-mesh sieve to obtain the South Pole drilling fluid filtrate reducer.

[0042] The infrared spectrum of the filtrate reducer obtained in this example is shown in Figure 1 , and the peaks corresponding to the stretching vibration peaks of N-H in the amide group are at 3400cm -1 , the asymmetric stretching vibration peaks of C-H are at 2950cm -1 , the symmetric stretching vibration peaks of C-H are at 2875cm -1 , the stretching vibration peaks of C=O in the amide group are at 1660cm -1 , the bending vibration peaks of N-H in the amide group are at 1620cm -1 , the bending vibration peaks of C-H in the methyl group are at 1480cm -1 , the stretching vibration peaks of C-N are at 1400cm -1 , the asymmetric stretching vibration peaks of C-O-C in the epoxy ring of (3-(oxirane-2-ylmethoxy)propyl)triethoxysilane are at 1250cm -1 , the symmetric stretching vibration peaks of Si-O-C in (3-(oxirane-2-ylmethoxy)propyl)triethoxysilane are at 1010cm -1 , and the in-plane vibration peaks of C-H of the ethoxyl group in (3-(oxirane-2-ylmethoxy)propyl)triethoxysilane are at 780cm -1 , the above experimental results prove that the target product is successfully prepared.

[0043] The transmission electron microscope image of the filtrate reducer obtained in this example is shown in Figure 2As shown, the image shows almost no obvious black shadow, and the edge of the image is thin. This indicates that the prepared fluid loss additive has uniform particle dispersion, and there is no accumulation of large particles. At the same time, the micro-morphology of the image also indicates that the lamella of the fluid loss additive particles is thin. These characteristics indicate that the prepared fluid loss additive can have excellent dispersibility in the drilling fluid. In addition, uniformly dispersed particles can impart a thin and dense mud cake to the drilling fluid to which the fluid loss additive is added, which makes the drilling fluid have excellent fluid loss performance. The above results indicate that the target product designed is successfully prepared.

[0044] Example 2

[0045] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that the reaction time in step (4) is 3 h, and other conditions are the same as in Example 1.

[0046] Example 3

[0047] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that in step (2), 4 g of (3-acrylamidopropyl) trimethylammonium chloride is added to 196 g of deionized water to obtain a quaternary ammonium salt solution with a mass concentration of 2 wt%, and other conditions are the same as in Example 1.

[0048] Example 4

[0049] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that in step (2), methacryloyloxyethyl trimethylammonium chloride is used instead of (3-acrylamidopropyl) trimethylammonium chloride, and other conditions are the same as in Example 1.

[0050] Example 5

[0051] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that in step (3), 1.2 g of (3-(oxirane-2-ylmethoxy)propyl) triethoxysilane is added to 78.8 g of deionized water to obtain an aqueous solution of (3-(oxirane-2-ylmethoxy)propyl) triethoxysilane with a mass concentration of 1.5 wt%, and other conditions are the same as in Example 1.

[0052] Example 6

[0053] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that the reaction time in step (5) is 3 h, and other conditions are the same as in Example 1.

[0054] Example 7

[0055] A method for preparing a fluid loss additive for an Antarctic drilling fluid is as described in Example 1, except that in step (1), the lithium magnesium silicate is replaced by montmorillonite.

[0056] Comparative Example 1

[0057] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (1), the lithium magnesium silicate is replaced by a rectorite, and other conditions are the same as in Example 1.

[0058] Comparative Example 2

[0059] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (1), the lithium magnesium silicate is replaced by a rectorite, and other conditions are the same as in Example 1.

[0060] Comparative Example 3

[0061] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (2), 10.0 g of (3-acrylamidopropyl) trimethylammonium chloride is added to 190 g of deionized water to obtain a quaternary ammonium salt solution with a mass concentration of 5 wt%, and other conditions are the same as in Example 1.

[0062] Comparative Example 4

[0063] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (2), (3-acrylamidopropyl) trimethylammonium chloride is replaced by diallyldimethylammonium chloride, and other conditions are the same as in Example 1.

[0064] Comparative Example 5

[0065] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (2), (3-acrylamidopropyl) trimethylammonium chloride is replaced by trimethylbenzylammonium chloride, and other conditions are the same as in Example 1.

[0066] Comparative Example 6

[0067] A preparation method of a filtrate reducer for Antarctic drilling fluid is as described in Example 1, except that in step (3), 0.8 g of (3-(oxetan-2-ylmethoxy)propyl) triethoxysilane is added to 79.2 g of deionized water to obtain an aqueous (3-(oxetan-2-ylmethoxy)propyl) triethoxysilane solution with a mass concentration of 1 wt%, and other conditions are the same as in Example 1.

[0068] Comparative Example 7

[0069] A preparation method of a filtration-reducing agent for Antarctic drilling fluid is as described in Embodiment 1, except that in step (3), 3.2 g of (3-(oxan-2-ylmethoxy)propyl)triethoxysilane is added to 76.8 g of deionized water to obtain an aqueous solution of (3-(oxan-2-ylmethoxy)propyl)triethoxysilane with a mass concentration of 4 wt%, and other conditions are the same as in Embodiment 1.

[0070] Comparative Example 8

[0071] A preparation method of a filtration-reducing agent for Antarctic drilling fluid is as described in Embodiment 1, except that in step (3), (3-(oxan-2-ylmethoxy)propyl)triethoxysilane is replaced by methyltriethoxysilane, and other conditions are the same as in Embodiment 1.

[0072] Comparative Example 9

[0073] A preparation method of a filtration-reducing agent for Antarctic drilling fluid is as described in Embodiment 1, except that in step (3), (3-(oxan-2-ylmethoxy)propyl)triethoxysilane is replaced by γ-aminopropyltriethoxysilane, and other conditions are the same as in Embodiment 1.

[0074] Comparative Example 10

[0075] A preparation method of a filtration-reducing agent for Antarctic drilling fluid is as described in Embodiment 1, except that in step (4), the reaction temperature is changed from 70°C to 50°C, and other conditions are the same as in Embodiment 1.

[0076] Comparative Example 11

[0077] A preparation method of a filtration-reducing agent for Antarctic drilling fluid is as described in Embodiment 1, except that in step (4), the reaction time is changed from 4 h to 2 h, and other conditions are the same as in Embodiment 1.

[0078] Test Example 1

[0079] The filtration-reducing agents prepared in the examples and comparative examples are tested for filtration performance, rheological performance, and colloidal dispersion performance.

[0080] (1) Drilling fluid preparation:

[0081] First, No. 4 aviation kerosene and No. 5 white oil are prepared into base oil at a volume ratio of 8:2; then, 3% of sodium dodecylbenzenesulfonate by mass of the base oil is added to the base oil and stirred for 20 min by a stirrer; finally, 2% of the filtration-reducing agent in the examples or comparative examples by mass of the base oil is added to the above system, and the system is further stirred for 25 min by the stirrer to prepare drilling fluid, which is tested for filtration, rheological performance, and colloidal dispersion.

[0082] (2) Test method:

[0083] Fluid loss test: first, the prepared drilling fluid is aged at-35℃ for 16h; then the API fluid loss of the drilling fluid is tested by the medium pressure fluid loss instrument at 100psi, and the test time is 7.5min. The measured fluid loss FL API = 2 x V 7.5min .

[0084] In the formula: FL API is the API fluid loss, mL; V 7.5min is the filtrate volume at 7.5min of the test, mL.

[0085] Rheological property test: the prepared drilling fluid is poured into a test slurry cup, and the rheological property of the drilling fluid at-35℃ is tested by a low temperature rheometer, and the measured parameters include apparent viscosity, plastic viscosity, dynamic shear force and static shear force.

[0086] Colloidal dispersion test: a certain amount of prepared drilling fluid is poured into a colorimetric tube, and then the colorimetric tube is placed in a low temperature constant temperature box (-35℃) for 16h, and then the colloidal rate is calculated, and the colloidal rate .

[0087] In the formula: Cr is the colloidal rate, %; V1 is the total volume of the drilling fluid, mL; V2 is the clear liquid volume of the upper layer, mL;

[0088] The test results of fluid loss, rheological property and colloidal dispersion are shown in Table 1.

[0089] Table 1: Performance test of the Antarctic drilling fluid fluid loss reducer

[0090]

[0091] As can be seen from the data in Table 1, the prepared fluid loss reducer can significantly improve the fluid loss performance, rheological property and colloidal dispersion of the Antarctic drilling fluid. The fluid loss of the drilling fluid to which the fluid loss reducer is added remains at 16-21mL after being aged at-35℃ for 16h, and the fluid loss performance is significantly reduced compared with the blank sample. At the same time, in terms of the rheological property change of the drilling fluid, the fluid loss reducer can increase the dynamic shear force of the drilling fluid at-35℃ from 0.75Pa to 2.0Pa, and the plastic viscosity is not increased much. In addition, the fluid loss reducer can keep the colloidal rate of the drilling fluid at-35℃ above 82.4%, and the colloidal dispersion stability of the drilling fluid is good.

[0092] In summary, the Antarctic drilling fluid fluid loss reducer of the application can meet the needs of polar drilling.

[0093] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details of the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0094] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0095] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A method for preparing a filtration loss reducer for Antarctic drilling fluid, characterized in that, The steps include the following: (1) Add layered silicate to deionized water, stir to hydrate, and obtain a suspension; the layered silicate is lithium magnesium silicate or montmorillonite; (2) Adjust the pH of the suspension obtained in step (1) to 7.5~8.5, add a quaternary ammonium salt solution, and react to obtain a reaction solution; the quaternary ammonium salt is methacryloyloxyethyltrimethylammonium chloride or (3-acrylamidopropyl)trimethylammonium chloride; the mass ratio of the quaternary ammonium salt in the quaternary ammonium salt solution to the layered silicate in the suspension is 1:2.2~3.5; the reaction temperature is 70~80℃; the reaction time is 3~5h; (3) Add an aqueous solution of (3-(ethylene oxide-2-ylmethoxy)propyl)triethoxysilane to the reaction solution obtained in step (2) and react. After the reaction is completed, centrifuge, dry and pulverize to obtain a filter loss reducer for Antarctic drilling fluid. The mass ratio of (3-(ethylene oxide-2-ylmethoxy)propyl)triethoxysilane in the aqueous solution of (3-(ethylene oxide-2-ylmethoxy)propyl)triethoxysilane to the layered silicate in the suspension is 1:7~10.

5.

2. The method for preparing the Antarctic drilling fluid filtration reducer according to claim 1, characterized in that, The temperature for stirring and hydration in step (1) is room temperature, and the stirring and hydration time is 1~2 hours.

3. The method for preparing the filtration loss reducer for Antarctic drilling fluid according to claim 1, characterized in that, The mass concentration of the suspension in step (1) is 3~5 wt%.

4. The method for preparing the filtration loss reducer for Antarctic drilling fluid according to claim 1, characterized in that, In step (2), the pH of the suspension is adjusted to 7.5-8.5 using a sodium hydroxide aqueous solution with a mass fraction of 20-30%.

5. The method for preparing the filtration loss reducer for Antarctic drilling fluid according to claim 1, characterized in that, The mass concentration of the quaternary ammonium salt solution in step (2) is 2~3 wt%.

6. The method for preparing the filtration loss reducer for Antarctic drilling fluid according to claim 1, characterized in that, The mass concentration of the aqueous solution of (3-(ethylene oxide-2-ylmethoxy)propyl)triethoxysilane in step (3) is 1.5~2.5wt%.

7. The method for preparing the filtration loss reducer for Antarctic drilling fluid according to claim 1, characterized in that, The reaction temperature in step (3) is 80~90℃; the reaction time is 1~3h; and the drying is vacuum drying at 50~60℃ for 10~15h.

8. A filtration loss reducer for Antarctic drilling fluids, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

9. The application of the Antarctic drilling fluid filtration reducer according to claim 8 in Antarctic drilling fluid, characterized in that, The Antarctic drilling fluid comprises base oil, surfactant, and filtration reducer for Antarctic drilling fluid. The base oil is obtained by mixing No. 4 aviation kerosene and No. 5 white oil in a volume ratio of 8:

2. The surfactant is sodium dodecylbenzene sulfonate, and the mass of the surfactant is 2-4% of the mass of the base oil. The mass of the filtration reducer for Antarctic drilling fluid is 1-3% of the mass of the base oil. The Antarctic drilling fluid is used in the drilling process of Antarctic ice layers and ice-rock interlayers.

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