Wide-temperature-range oil-base-resistant drilling fluid composite material and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a wide-temperature-range oil-base-resistant drilling fluid composite material and a preparation method thereof.The composite material comprises hydrogenated butadiene-acrylonitrile rubber, acrylate rubber, butadiene rubber, polyvinyl chloride resin, N, N-dimethylformamide, a coupling agent and an antioxidant. The rubber material is prepared from N, N '-m-phenylenedimaleimide, dibutoxyethoxyethyl adipate, triisooctyl phosphite, silicon dioxide, an anti-aging agent, carbon black, a vulcanizing aid and a process aid. According to the composite material provided by the invention, through the synergistic effect of all the components, the composite material with the use temperature range of-50 DEG C to 160 DEG C and good drilling fluid tolerance can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a composite material of hydrogenated nitrile rubber and polyvinyl chloride resin for preparing wide-temperature-range oil-resistant drilling fluid and a preparation method thereof. Background Art

[0002] At present, the drilling fluids used in drilling are mainly divided into water-based and oil-based. Oil-based drilling fluids have been widely used in underbalanced drilling due to their advantages such as high temperature resistance and fast drilling speed. The components in oil-based drilling fluids generally contain 60-90% aromatic hydrocarbons, which will have a strong swelling property on rubber materials; the drilling fluid is an alkaline mixture with a pH value greater than 10, which will produce a greater resistance to alkaline corrosion on the material. The climatic environment of the drilling site is relatively harsh, especially in high-cold areas where the lowest temperature is close to -40°C, and the local maximum temperature of the drilling fluid that the sealing material contacts can reach more than 150°C. If the sealing material cannot meet all of the above conditions, it will seriously affect the sealing performance and service life. Therefore, higher requirements are placed on the performance of sealing materials used under oil-based drilling fluid conditions.

[0003] Hydrogenated nitrile rubber is a highly saturated elastomer with good oil resistance. Due to its highly saturated structure, it also has good heat resistance, chemical corrosion resistance, ozone resistance, and high resistance to compression permanent deformation. It also has high strength, high tear resistance, high wear resistance and other properties. It is one of the rubbers with excellent comprehensive properties and is widely used in oil fields, automotive industry and other fields.

[0004] However, at present, the operating temperature of pure HNBR is mostly -40℃-150℃. For ultra-deep well operations in extremely cold areas, it is impossible to meet the low temperature requirements while meeting the working conditions where the local maximum temperature is higher than 150℃. How to effectively expand the scope of use of hydrogenated nitrile rubber materials while ensuring the comprehensive performance of hydrogenated nitrile rubber is an important research direction for the application of HNBR. Therefore, providing oil-resistant hydrogenated nitrile composite materials for drilling fluids with a wide temperature range has high economic value and market prospects. Summary of the invention

[0005] The present invention blends hydrogenated nitrile rubber, acrylic rubber, butadiene rubber and polyvinyl chloride resin by a rubber-plastic blending method, and provides a wide temperature range oil-resistant base drilling fluid composite material and a preparation method thereof. The composite material has a use temperature range of -50°C to 160°C and good drilling fluid tolerance. The composite material contains the following components by mass:

[0006] Hydrogenated nitrile rubber 25%-30%, acrylic rubber 12%-15%, butadiene rubber 6%-10%, polyvinyl chloride resin 5%-8%, N, N'-m-phenylene bismaleimide 0.5%-1%, dibutyloxyethoxyethyl adipate 4%-5%, triisooctyl phosphite 4%-5%, silicon dioxide 6%-9%, antioxidant 1.5%-2%, carbon black 15%-20%, vulcanizing agent 3%-4%, process additive 1%-2%, zinc oxide 3%-4%, magnesium oxide 2%-3%, stearic acid 0.5%-1%;

[0007] In the hydrogenated nitrile rubber, the content of hydrogenated structural units provided by acrylonitrile is 33% by weight, and the double bond content of the hydrogenated nitrile rubber is less than 1%;

[0008] The polyvinyl chloride resin is selected from SG5 type;

[0009] The silicon dioxide is produced by gas phase method;

[0010] The vulcanizing agent is di-(tert-butyl peroxyisopropyl)benzene and thiocyanate;

[0011] The antioxidant is composed of DDA antioxidant and MmBIC in a ratio of 3:2.

[0012] The process additive is composed of CTU and SC617 in a ratio of 1:1;

[0013] A method for preparing a wide temperature range oil-resistant base drilling fluid composite material is as follows:

[0014] (1) Main material blending:

[0015] a. Add polyvinyl chloride resin, dibutoxyethoxyethyl adipate, N,N'-m-phenylene bismaleimide in a ratio of 100:25:3 into a horizontal stirring tank, stir at a speed of 60r / min for 40min, and maintain the pressure of the stirring tank at 0.25Mpa;

[0016] b. Put hydrogenated nitrile rubber and acrylic rubber into the open mill, keep the roller distance at 0.5mm, pass the thin mill 12 times, and leave it for later use;

[0017] c. The hydrogenated nitrile rubber and acrylate rubber blend plasticized in step b is put into an internal mixer. When the internal mixer is heated to 150-155°C and the pressure is 0.55-0.65Mpa, the material prepared in step a and butadiene rubber are added and blended according to the formula ratio. The blending time is 10-12min.

[0018] d. The blended composite material is put into an open mill for 6 passes of thin-pass pressing, and the roller distance is widened to 8 mm to produce a sheet to obtain the main material of the wide temperature range oil-based drilling fluid resistant composite material.

[0019] (2) Secondary plasticizing: plasticize the blended main materials in an open mill, thin pass 8-10 times, and plasticize until the Mooney viscosity ML1+4 at 125°C is less than or equal to 55;

[0020] (3) Mixing: The main material after the secondary plasticization is transferred to an internal mixer, and 1 part of antioxidant MmBIC, 1.5 parts of antioxidant DDA-70, 2 parts of CTU, 2 parts of SC617, and 6-10 parts of fumed silica are added, and the mixture is added to the internal mixer in sequence for internal mixing, wherein the rotor speed of the internal mixer is 32 r / min, and the mixing time is 300 seconds; after the internal mixing, 30-45 parts of carbon black, 6-12 parts of triisooctyl phosphite, 5 parts of zinc oxide, 4 parts of magnesium oxide, and 1 part of stearic acid are added and mixed, and the mixing temperature is 130-140° C., and the mixing time is 300 seconds. The mixed rubber is discharged from the mixing and passed through an open mill for 3-4 times, and then the film is hung to dry. After the film is left for 8-12 hours, it is put into the open mill again and 4.5 parts of vulcanizing agent is added, and the film is passed through 4-5 times, and then the film is cooled to obtain a mixed film;

[0021] (4) Vulcanization: After the mixed rubber sheet is left standing for 12 hours, the mixed rubber sheet is heat-refined to obtain re-mixed rubber, the re-mixed rubber is loaded into a mold, and placed on a flat vulcanizer for vulcanization to obtain a finished product, wherein the vulcanization time is 15 minutes, the vulcanization temperature is 170°C, and the vulcanization pressure is 15 MPa.

[0022] Compared with the prior art, the present invention has at least the following advantages:

[0023] 1. The composite material provided by the present invention has similar physical and mechanical properties and aging properties to hydrogenated nitrile rubber through the synergistic coordination between various components of specific types and contents; and has better tear strength, wear resistance and low temperature resistance than hydrogenated nitrile rubber;

[0024] 2. The composite material provided by the present invention achieves a widened temperature range of the material by blending a variety of polymer materials. The introduction of butadiene rubber and the use of dibutyloxyethoxyethyl adipate effectively reduce the low temperature resistance of the material, and the brittle temperature of the material is reduced from -40°C to -50°C; the introduction of acrylic rubber increases the high temperature resistance of the material from 150°C to 160°C.

[0025] 3. The composite material provided by the present invention improves the wear resistance and drilling fluid resistance of the material by introducing polyvinyl chloride. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with embodiments.

[0027] Example

[0028] (1) Main material blending:

[0029] a. Add polyvinyl chloride resin, dibutoxyethoxyethyl adipate, N,N'-m-phenylene bismaleimide in a ratio of 100:25:3 into a horizontal stirring tank, stir at a speed of 60r / min for 40min, and maintain the pressure of the stirring tank at 0.25Mpa;

[0030] b. Put hydrogenated nitrile rubber and acrylic rubber into the open mill, keep the roller distance at 0.5mm, pass the thin mill 12 times, and leave it for later use;

[0031] c. The hydrogenated nitrile rubber and acrylate rubber blend plasticized in step b is put into an internal mixer. When the internal mixer is heated to 155°C and the pressure is 0.60Mpa, the material prepared in step a and butadiene rubber are added and blended according to the formula ratio. The blending time is 10 to 12min.

[0032] d. The blended composite material is put into an open mill for 6 passes of thin-pass pressing, and the roller distance is widened to 8 mm to produce a sheet to obtain the main material of the wide temperature range oil-based drilling fluid resistant composite material.

[0033] (2) Secondary plasticizing: plasticize the blended main material in an open mill, thin pass 10 times, and plasticize until the Mooney viscosity ML1+4 at 125°C is less than or equal to 55;

[0034] (3) Mixing: the raw rubber obtained after the secondary plasticizing is transferred to an internal mixer, and 1 part of antioxidant MmBIC, 1.5 parts of antioxidant DDA-70, 2 parts of CTU, 2 parts of SC617, and 10 parts of silicon dioxide are added to the internal mixer in sequence for internal mixing, wherein the internal mixer rotor speed is 32 r / min, and the internal mixing time is 300 s; after internal mixing, 40 parts of carbon black, 8 parts of triisooctyl phosphite, 5 parts of zinc oxide, 4 parts of magnesium oxide, and 1 part of stearic acid are added and mixed, and the mixing temperature is 135° C. and the mixing time is 300 s. The mixed rubber is discharged and passed through an open mixer for thinning 4 times, and then the film is hung to dry. After the film is left for 12 hours, it is put into the open mixer again and 4.5 parts of vulcanizing agent are added. After thinning 5 times, the film is cooled to obtain a mixed rubber;

[0035] (4) Vulcanization: After the mixed rubber sheet is left for 12 hours, the mixed rubber sheet is heat-refined to obtain re-refined rubber, which is then put into a mold and placed on a flat vulcanizer for vulcanization to obtain a finished product, wherein the vulcanization time is 15 minutes, the vulcanization temperature is 170°C, and the vulcanization pressure is 15 MPa. Thus, a wide temperature range oil-based drilling fluid resistant composite material is obtained.

[0036] Under the same formulation framework, the specific performance comparison between the wide temperature range oil-resistant base drilling fluid composite material of the present invention and the hydrogenated nitrile rubber material is as follows:

[0037] Table 1 Performance of wide temperature range oil-based drilling fluid composite materials

[0038]

[0039]

[0040] It can be seen that the wide temperature range oil-resistant drilling fluid composite material prepared by the present invention has similar physical and mechanical properties and aging properties to those of hydrogenated nitrile rubber; its tear strength and wear resistance are better than those of hydrogenated nitrile rubber; its brittle temperature is 10°C lower than that of hydrogenated nitrile rubber; and its aging performance at 160°C is significantly better than that of hydrogenated nitrile rubber.

[0041] Example 1

[0042] Different amounts of fumed silica have a significant impact on the physical and mechanical properties and wear resistance of the vulcanized rubber, especially the tear resistance. Table 2 shows the effects of different amounts of silica on the physical and mechanical properties of the vulcanized rubber.

[0043] Table 2 Effect of different amounts of white carbon black on the physical and mechanical properties of vulcanized rubber

[0044]

[0045] Example 2

[0046] Different carbon black dosages have a great influence on the mechanics of vulcanized rubber. Table 3 shows the effects of different proportions of carbon black dosage on the physical and mechanical properties of vulcanized rubber.

[0047] Table 3 Effect of different proportions of carbon black on the physical and mechanical properties of vulcanized rubber

[0048]

[0049] In summary, it can be seen from the above results that the wide temperature range oil-resistant base drilling fluid composite material prepared according to the method of the present invention has physical and mechanical properties and aging properties that are almost the same as those of hydrogenated nitrile rubber; it is superior to hydrogenated nitrile rubber in tear strength, wear resistance and high and low temperature resistance; it can adapt to operating conditions in a wider temperature range, and therefore has a higher economic value.

Claims

1. A wide temperature range oil-resistant drilling fluid composite material, characterized in that: The composite material contains the following components by mass: Hydrogenated nitrile rubber 25%-30%, acrylic rubber 12%-15%, butadiene rubber 6%-10%, polyvinyl chloride resin 5%-8%, N, N'-m-phenylene bismaleimide 0.5%-1%, dibutyloxyethoxyethyl adipate 4%-5%, triisooctyl phosphite 4%-5%, silicon dioxide 6%-9%, antioxidant 1.5%-2%, carbon black 15%-20%, vulcanizing agent 3%-4%, process additive 1%-2%, zinc oxide 3%-4%, magnesium oxide 2%-3%, stearic acid 0.5%-1%; In the hydrogenated nitrile rubber, the content of hydrogenated structural units provided by acrylonitrile is 33% by weight, and the double bond content of the hydrogenated nitrile rubber is less than 1%; The polyvinyl chloride resin is selected from SG5 type; The silicon dioxide is produced by a gas phase method.

2. The wide temperature range oil-resistant drilling fluid composite material according to claim 1, characterized in that: The vulcanizing agent is di-(tert-butyl peroxyisopropyl)benzene and thiocyanate.

3. The wide temperature range oil-resistant drilling fluid composite material according to claim 1, characterized in that: The antioxidant is composed of DDA antioxidant and MmBIC in a ratio of 3:

2.

4. The wide temperature range oil-resistant drilling fluid composite material according to claim 1, characterized in that: The process additive is composed of CTU and SC617 in a ratio of 1:

1.

5. A method for preparing a wide temperature range oil-resistant drilling fluid composite material, characterized in that: The method comprises the following steps: (1) Main material blending: a. Add polyvinyl chloride resin, dibutoxyethoxyethyl adipate, N,N'-m-phenylene bismaleimide in a ratio of 100:25:3 into a horizontal stirring tank, stir at a speed of 60r / min for 40min, and maintain the pressure of the stirring tank at 0.25Mpa; b. Put hydrogenated nitrile rubber and acrylic rubber into the open mill, keep the roller distance at 0.5mm, pass the thin mill 12 times, and leave it for later use; c. The hydrogenated nitrile rubber and acrylate rubber blend plasticized in step b is put into an internal mixer. When the internal mixer is heated to 150-155°C and the pressure is 0.55-0.65Mpa, the material prepared in step a and butadiene rubber are added and blended according to the formula ratio. The blending time is 10-12min. d. The blended composite material is put into a thin open mill and pressed 6 times, and the roller spacing is widened to 8mm to obtain the main material of a wide temperature range oil-resistant drilling fluid composite material; (2) Secondary plasticizing: plasticize the blended main materials in an open mill, thin pass 8-10 times, and plasticize until the Mooney viscosity ML1+4 at 125°C is less than or equal to 55; (3) Mixing: The main material after the secondary plasticization is transferred to an internal mixer, and 1 part of antioxidant MmBIC, 1.5 parts of antioxidant DDA-70, 2 parts of CTU, 2 parts of SC617, and 6-10 parts of fumed silica are added, and the mixture is added to the internal mixer in sequence for internal mixing, wherein the rotor speed of the internal mixer is 32 r / min, and the mixing time is 300 seconds; after the internal mixing, 30-45 parts of carbon black, 6-12 parts of triisooctyl phosphite, 5 parts of zinc oxide, 4 parts of magnesium oxide, and 1 part of stearic acid are added and mixed, and the mixing temperature is 130-140° C., and the mixing time is 300 seconds. The mixed rubber is discharged from the mixing and passed through an open mill for 3-4 times, and then the film is hung to dry. After the film is left for 8-12 hours, it is put into the open mill again and 4.5 parts of vulcanizing agent is added, and the film is passed through 4-5 times, and then the film is cooled to obtain a mixed film; (4) Vulcanization: After the mixed rubber sheet is left standing for 12 hours, the mixed rubber sheet is heat-refined to obtain re-mixed rubber, the re-mixed rubber is loaded into a mold, and placed on a flat vulcanizer for vulcanization to obtain a finished product, wherein the vulcanization time is 15 minutes, the vulcanization temperature is 170°C, and the vulcanization pressure is 15 MPa.

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