Emulsified asphalt filtrate reducer for high-temperature-resistant drilling fluid and preparation method of emulsified asphalt filtrate reducer
By modifying the combination of asphalt, carbon nanotubes and ethylene-vinyl acetate copolymer, an anti-high-temperature emulsified asphalt filter reduction loss agent is prepared, which solves the problem of insufficient filtration loss performance in high-temperature environment and improves the stability and sealing ability of the drilling fluid.
Patent Information
- Application Number
- CN202510598165.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-09
- Publication Date
- 2025-08-01
AI Technical Summary
The existing emulsified asphalt filter loss agent has insufficient performance in high-temperature environments and cannot meet the performance requirements of drilling fluid applications.
Using a combination of modified bitumen, carbon nanotubes and ethylene-vinyl acetate copolymer, a modified substance is formed by heating melting and shearing treatment, and an emulsified bitumen filter reduction agent is prepared together with an emulsifier, stabilizer and surfactant to enhance its high temperature resistance.
It significantly improves the resistance to high-temperature filter loss loss performance of emulsified asphalt filter loss loss agent, enhances the stability and sealing ability of drilling fluid, and prevents the well wall from collapse and peeling.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of treatment agents for drilling fluids, and specifically, to an emulsified asphalt filtrate reducer for high-temperature resistant drilling fluids and a preparation method thereof. Background Art
[0002] With the continuous growth of global energy demand, the exploitation of oil and gas has become an important energy strategy. During the deep well drilling process, to meet the requirements of drilling operations, water-based drilling fluids are widely used due to their cost-effective advantages. During the drilling process, when the drilling fluid contacts the formation, the water and fine particles in it will infiltrate into the formation. If the filtrate loss is too large, the formation around the wellbore will lose support, and collapse and spalling are likely to occur. This will not only damage the drilling equipment but may also cause serious accidents such as blowouts. Therefore, the control of the filtrate loss of the drilling fluid has become one of the key factors to ensure the smooth progress of drilling operations. Emulsified asphalt filtrate reducers are a type of functional additive for controlling the filtrate loss of drilling fluids and play an important role in maintaining the performance of drilling fluids and stabilizing the wellbore. However, the current emulsified asphalt filtrate reducers have limited filtrate reduction performance and are easily affected by high-temperature environments, thereby reducing the filtrate reduction performance of emulsified asphalt filtrate reducers and cannot meet the application performance requirements. Therefore, improving the high-temperature resistant filtrate reduction performance of emulsified asphalt filtrate reducers is a technical problem that needs to be solved urgently at present. Summary of the Invention
[0003] The present invention provides an emulsified asphalt filtrate reducer for high-temperature resistant drilling fluids and a preparation method thereof, which solves the problem of poor high-temperature resistant filtrate reduction performance of emulsified asphalt filtrate reducers for drilling fluids in the related art.
[0004] The technical solution of the present invention is as follows: The present invention provides an emulsified asphalt filtrate reducer for high-temperature resistant drilling fluids, comprising the following components in parts by weight: 60 - 80 parts of modified asphalt, 1 - 3 parts of emulsifier, 0.5 - 2 parts of stabilizer, 2 - 6 parts of surfactant, and 100 parts of water; The raw materials of the modified asphalt include asphalt, carbon nanotubes, and ethylene-vinyl acetate copolymer.
[0005] As a further technical solution, the weight ratio of the asphalt, carbon nanotubes, and ethylene-vinyl acetate copolymer is 11 - 32:2:1.
[0006] When the weight ratio of the asphalt, carbon nanotubes, and ethylene-vinyl acetate copolymer is 11 - 32:2:1, the high-temperature resistant filtrate reduction performance of the emulsified asphalt filtrate reducer for drilling fluids can be further improved.
[0007] As a further technical solution, the preparation method of the modified asphalt comprises the following steps: A1. Heat the ethylene-vinyl acetate copolymer until it melts, add carbon nanotubes, and disperse them evenly to obtain a modified product; A2. Heat the asphalt until it melts, shear it, add the modified product, and shear again to obtain modified asphalt.
[0008] As a further technical solution, in step A1, when heating and melting, the temperature is 100-110°C; in step A2, when heating and melting, the temperature is 80-90°C.
[0009] As a further technical solution, the carbon nanotubes are modified carbon nanotubes, and the raw materials of the modified carbon nanotubes include carbon nanotubes and 4-aminophthalic acid.
[0010] Using 4-aminophthalic acid to modify the surface of carbon nanotubes can not only make the carbon nanotubes disperse more evenly, but also strengthen the effective combination with asphalt, thereby making the emulsification effect of asphalt better, forming an emulsified asphalt filtrate reducer for drilling fluid with a more stable internal structure, and further improving the high-temperature filtration reduction performance of the emulsified asphalt filtrate reducer for drilling fluid.
[0011] As a further technical solution, the weight ratio of the carbon nanotubes to 4-aminophthalic acid is 9-19:1.
[0012] When the weight ratio of the carbon nanotubes to 4-aminophthalic acid is 9-19:1, the high-temperature filtration reduction performance of the emulsified asphalt filtrate reducer for drilling fluid can be further improved.
[0013] As a further technical solution, the preparation method of the modified carbon nanotubes includes the following steps: dissolve the 4-aminophthalic acid in ethyl acetate to obtain a 4-aminophthalic acid solution, add the carbon nanotubes to the 4-aminophthalic acid solution, disperse them evenly, and dry to obtain the modified carbon nanotubes.
[0014] As a further technical solution, the mass fraction of the 4-aminophthalic acid solution is 3%-10%.
[0015] As a further technical solution, the emulsifier is one or more of sodium alkylbenzene sulfonate, sodium alkyl sulfonate, and octadecyl trimethyl ammonium chloride; the stabilizer is one or two of sodium chloride and calcium chloride; the surfactant is one or two of polyethylene glycol and benzalkonium bromide.
[0016] The present invention also provides a preparation method of the above-mentioned emulsified asphalt filtrate reducer for high-temperature resistant drilling fluid, including the following steps: S1. Dissolve the stabilizer and surfactant in water, add an emulsifier, and adjust the pH value to obtain a mixed solution; S2. Add the modified asphalt into the mixed solution and emulsify it to obtain an emulsified asphalt filtrate reducer for drilling fluid.
[0017] As a further technical solution, in step S1, when dissolving, the temperature is 60 - 80°C; when adjusting the pH value, the pH value is adjusted to 4.5 - 5.5.
[0018] As a further technical solution, in step S1, when adjusting the pH value, a hydrochloric acid solution with a mass fraction of 5% - 8% is used.
[0019] The working principle and beneficial effects of the present invention are as follows: In the present invention, the asphalt is modified by using carbon nanotubes and ethylene - vinyl acetate copolymer. While improving the internal structural stability of the emulsified asphalt filtrate reducer for drilling fluid, it can enhance the contact area between the emulsified asphalt filtrate reducer for drilling fluid and the formation pore wall surface, improve its plugging ability, and thus significantly improve the high - temperature resistant filtrate reduction performance of the emulsified asphalt filtrate reducer for drilling fluid. Specific Embodiments
[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.
[0021] In the following embodiments and comparative examples, the particle size of the asphalt is 100 mesh, and the model is WTD005; the carbon nanotubes are multi - wall carbon nanotubes with a tube diameter of 9.5 nm and a length of 1.5 μm, the product number is 0601004, and the manufacturer is Forsman Technology (Beijing) Co., Ltd.; the model of the ethylene - vinyl acetate copolymer is EVA 7760S; the emulsifier is octadecyl trimethyl ammonium chloride; the stabilizer is sodium chloride; the surfactant is polyethylene glycol, and the model is PGE - 300.
[0022] Example 1 An emulsified asphalt filtrate reducer for high - temperature resistant drilling fluid, comprising the following components in parts by weight: 60 parts of modified asphalt, 1 part of octadecyl trimethyl ammonium chloride, 0.5 part of sodium chloride, 2 parts of polyethylene glycol, 100 parts of water; The raw materials of the modified asphalt include 42 parts of asphalt, 12 parts of carbon nanotubes, and 6 parts of ethylene - vinyl acetate copolymer; The preparation method of the modified asphalt includes the following steps: A1. Heat and melt 6 parts of ethylene - vinyl acetate copolymer at 100°C, add 12 parts of carbon nanotubes, and disperse evenly to obtain a modified product; A2. Heat and melt 42 parts of asphalt at 80°C, shear, add the modifier, and shear to obtain modified asphalt.
[0023] A preparation method of an emulsified asphalt filtration reducer for drilling fluid, comprising the following steps: S1. Dissolve sodium chloride and polyethylene glycol in water at 60°C, add octadecyltrimethylammonium chloride, and then adjust the pH value to 4.5 with an 8% hydrochloric acid solution to obtain a mixed solution; S2. Add modified asphalt to the mixed solution, emulsify and disperse evenly to obtain an emulsified asphalt filtration reducer for drilling fluid.
[0024] Example 2 An emulsified asphalt filtration reducer for high-temperature resistant drilling fluid, comprising the following components in parts by weight: 70 parts of modified asphalt, 2 parts of octadecyltrimethylammonium chloride, 1.5 parts of sodium chloride, 4 parts of polyethylene glycol, 100 parts of water; The raw materials of the modified asphalt include 52 parts of asphalt, 12 parts of carbon nanotubes, and 6 parts of ethylene-vinyl acetate copolymer; The preparation method of the modified asphalt comprises the following steps: A1. Heat and melt 6 parts of ethylene-vinyl acetate copolymer at 105°C, add 12 parts of carbon nanotubes, and disperse evenly to obtain a modifier; A2. Heat and melt 52 parts of asphalt at 85°C, shear, add the modifier, and shear to obtain modified asphalt.
[0025] A preparation method of an emulsified asphalt filtration reducer for drilling fluid, comprising the following steps: S1. Dissolve sodium chloride and polyethylene glycol in water at 70°C, add octadecyltrimethylammonium chloride, and then adjust the pH value to 5 with an 8% hydrochloric acid solution to obtain a mixed solution; S2. Add modified asphalt to the mixed solution, emulsify and disperse evenly to obtain an emulsified asphalt filtration reducer for drilling fluid.
[0026] Example 3 An emulsified asphalt filtration reducer for high-temperature resistant drilling fluid, comprising the following components in parts by weight: 80 parts of modified asphalt, 3 parts of octadecyltrimethylammonium chloride, 2 parts of sodium chloride, 6 parts of polyethylene glycol, 100 parts of water; The raw materials of the modified asphalt include 62 parts of asphalt, 12 parts of carbon nanotubes, and 6 parts of ethylene-vinyl acetate copolymer; The preparation method of the modified asphalt comprises the following steps: A1. Heat and melt 6 parts of ethylene-vinyl acetate copolymer at 110°C, add 12 parts of carbon nanotubes, and disperse evenly to obtain a modifier; A2. Heat 62 parts of asphalt to melt at 90°C, shear, add the modifier, and shear again to obtain modified asphalt.
[0027] A preparation method of an emulsified asphalt filtrate reducer for drilling fluid, comprising the following steps: S1. Dissolve sodium chloride and polyethylene glycol in water at 80°C, add octadecyl trimethyl ammonium chloride, and then adjust the pH value to 5.5 with an 8% hydrochloric acid solution to obtain a mixed solution; S2. Add modified asphalt to the mixed solution, emulsify and disperse evenly to obtain an emulsified asphalt filtrate reducer for drilling fluid.
[0028] Example 4 The difference between this example and Example 2 is only that in this example, the raw materials of the modified asphalt include 67 parts of asphalt, 2 parts of carbon nanotubes, and 1 part of ethylene-vinyl acetate copolymer.
[0029] Example 5 The difference between this example and Example 2 is only that in this example, the raw materials of the modified asphalt include 64 parts of asphalt, 4 parts of carbon nanotubes, and 2 parts of ethylene-vinyl acetate copolymer.
[0030] Example 6 The difference between this example and Example 2 is only that in this example, the raw materials of the modified asphalt include 55 parts of asphalt, 10 parts of carbon nanotubes, and 5 parts of ethylene-vinyl acetate copolymer.
[0031] Example 7 The difference between this example and Example 6 is only that in this example, the carbon nanotubes are modified carbon nanotubes, and the preparation method of the modified carbon nanotubes includes the following steps: Dissolve 1.5 parts of 4-aminophthalic acid in ethyl acetate to obtain a 4% 4-aminophthalic acid solution by mass fraction. Add 8.5 parts of carbon nanotubes to the 4% 4-aminophthalic acid solution by mass fraction, disperse evenly, and dry to obtain modified carbon nanotubes.
[0032] Example 8 The difference between this example and Example 7 is only that in this example, 9.6 parts of carbon nanotubes and 0.4 parts of 4-aminophthalic acid are added.
[0033] Example 9 The difference between this example and Example 7 is only that in this example, 9 parts of carbon nanotubes and 1 part of 4-aminophthalic acid are added.
[0034] Example 10 The difference between this example and Example 7 is only that in this example, 9.5 parts of carbon nanotubes and 0.5 parts of 4-aminophthalic acid are added.
[0035] Comparative Example 1 The difference between this comparative example and Example 1 is only that in this comparative example, the raw materials of the modified asphalt include 42 parts of asphalt and 18 parts of ethylene-vinyl acetate copolymer, and the preparation method of the modified asphalt includes the following steps: after heating and melting 42 parts of asphalt, 18 parts of ethylene-vinyl acetate copolymer are added and sheared to obtain the modified asphalt.
[0036] Comparative Example 2 The difference between this comparative example and Example 1 is only that in this comparative example, the raw materials of the modified asphalt include 42 parts of asphalt and 18 parts of carbon nanotubes, and the preparation method of the modified asphalt includes the following steps: after heating and melting 42 parts of asphalt, 18 parts of carbon nanotubes are added and sheared to obtain the modified asphalt.
[0037] Comparative Example 3 The difference between this comparative example and Example 1 is only that in this comparative example, 60 parts of the modified asphalt are replaced with an equal amount of asphalt.
[0038] Experimental Example Filtration Loss Reduction Performance Test Base Mud Preparation: 16 g of bentonite (sodium-based bentonite, particle size 325 mesh) and 1.2 g of anhydrous sodium carbonate are added to 400 mL of water, and high-speed stirring is carried out at a stirring speed of 10000 r / min for 30 min, and cured at room temperature for 24 h to obtain the base mud; The emulsified asphalt filtration loss reducer for drilling fluid prepared in Examples 1 to 10 and Comparative Examples 1 to 3 is added to the base mud (the addition amount of the emulsified asphalt filtration loss reducer for drilling fluid is 3% of the volume of the base mud), and high-speed stirring is carried out at a stirring speed of 10000 r / min for 40 min. The prepared base mud and the emulsified asphalt filtration loss reducer sample for drilling fluid are heat-rolled at 120 °C and 150 °C for 16 h respectively, and the filtration loss is measured. The test results are shown in Table 1 below.
[0039] Table 1 Filtration Loss Reduction Performance Test Results
[0040] Taking the base mud as a blank sample, when the emulsified asphalt filtration loss reducer for drilling fluid prepared in Examples 1 to 3 is added to the base mud and heat-rolled at 120 °C and 150 °C for 16 h respectively, the filtration loss is significantly less than 15 mL, indicating that the emulsified asphalt filtration loss reducer for drilling fluid prepared by this scheme has good high-temperature filtration loss reduction performance.
[0041] Compared with Comparative Examples 1 to 3, when the emulsified asphalt filtration reducer for drilling fluid prepared in Example 1 was added to the base slurry and heat-rolled at 120 °C and 150 °C for 16 h respectively, the filtration loss amount decreased significantly, indicating that modifying asphalt with carbon nanotubes and ethylene-vinyl acetate copolymer can significantly improve the high-temperature filtration loss reduction performance of the emulsified asphalt filtration reducer for drilling fluid.
[0042] Compared with Examples 2 and 4, when the emulsified asphalt filtration reducers for drilling fluid prepared in Examples 5 to 6 were added to the base slurry and heat-rolled at 120 °C and 150 °C for 16 h respectively, the filtration loss amount decreased significantly, indicating that when the weight ratio of asphalt, carbon nanotubes and ethylene-vinyl acetate copolymer is 11 - 32:2:1, the high-temperature filtration loss reduction performance of the emulsified asphalt filtration reducer for drilling fluid can be further improved.
[0043] Compared with Example 6, when the emulsified asphalt filtration reducers for drilling fluid prepared in Examples 7 to 10 were added to the base slurry and heat-rolled at 120 °C and 150 °C for 16 h respectively, the filtration loss amount decreased significantly, indicating that surface modification of carbon nanotubes with 4-aminophthalic acid can further improve the high-temperature filtration loss reduction performance of the emulsified asphalt filtration reducer for drilling fluid. Compared with Examples 7 to 8, when the emulsified asphalt filtration reducers for drilling fluid prepared in Examples 9 to 10 were added to the base slurry and heat-rolled at 120 °C and 150 °C for 16 h respectively, the filtration loss amount decreased significantly, indicating that when the weight ratio of carbon nanotubes and 4-aminophthalic acid is 9 - 19:1, the high-temperature filtration loss reduction performance of the emulsified asphalt filtration reducer for drilling fluid can be further improved.
[0044] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. An emulsified asphalt filtrate reducer for high-temperature resistant drilling fluid, characterized in that It comprises components in the following parts by weight: 60 - 80 parts of modified asphalt, 1 - 3 parts of emulsifier, 0.5 - 2 parts of stabilizer, 2 - 6 parts of surfactant, 100 parts of water; The raw materials of the modified asphalt include asphalt, carbon nanotubes and ethylene - vinyl acetate copolymer.
2. The emulsified asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 1, wherein The weight ratio of the asphalt, carbon nanotubes and ethylene - vinyl acetate copolymer is 11 - 32:2:
1.
3. The emulsified asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 2, characterized in that, The preparation method of the modified asphalt comprises the following steps: A1. Heat the ethylene - vinyl acetate copolymer to melt, add carbon nanotubes, and disperse evenly to obtain a modified product; A2. Heat the asphalt to melt, shear, add the modified product, and shear to obtain the modified asphalt.
4. An emulsion asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 1, characterized in that, The carbon nanotubes are modified carbon nanotubes, and the raw materials of the modified carbon nanotubes include carbon nanotubes and 4 - aminophthalic acid.
5. An emulsified asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 4, characterized in that, The weight ratio of the carbon nanotubes and 4 - aminophthalic acid is 9 - 19:
1.
6. The emulsified asphalt filtrate reducer for high-temperature resistant drilling fluid according to claim 4, characterized in that, The preparation method of the modified carbon nanotubes comprises the following steps: Dissolve the 4 - aminophthalic acid in ethyl acetate to obtain a 4 - aminophthalic acid solution, add the carbon nanotubes into the 4 - aminophthalic acid solution, disperse evenly, and dry to obtain the modified carbon nanotubes.
7. An emulsified asphalt filtrate reducer for high-temperature resistant drilling fluid according to claim 1, characterized in that, The emulsifier is one or more of sodium alkylbenzene sulfonate, sodium alkyl sulfonate, octadecyl trimethyl ammonium chloride; the stabilizer is one or two of sodium chloride and calcium chloride; the surfactant is one or two of polyethylene glycol and benzalkonium bromide.
8. The preparation method of an emulsified asphalt filtrate reducer for high-temperature resistant drilling fluid according to any one of claims 1 to 7, characterized in that, It comprises the following steps: S1. Add the stabilizer and surfactant into water to dissolve, add the emulsifier, and adjust the pH value to obtain a mixed solution; S2. Add the modified asphalt into the mixed solution and emulsify to obtain an emulsified asphalt filtration reducer for drilling fluid.
9. The preparation method of an emulsified asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 8, characterized in that, In step S1, during the dissolution, the temperature is 60 - 80°C; when adjusting the pH value, the pH value is adjusted to 4.5 - 5.
5.
10. The preparation method of an emulsified asphalt filtration reducer for high-temperature resistant drilling fluid according to claim 8, characterized in that, In step S1, when adjusting the pH value, a hydrochloric acid solution with a mass fraction of 5% - 8% is used.