Oil well cement defoaming agent based on dimethyl silicone oil and preparation process thereof

Abstract

The invention relates to the technical field of defoaming agents, in particular to an oil well cement defoaming agent based on simethicone and a preparation process of the oil well cement defoaming agent based on simethicone. Block combination of silicone oil and polyether chain segments is achieved through reaction of double-end-group hydrogen-containing silicone oil and diallyl polyoxyethylene polyoxypropylene ether; according to the present invention, with the polyether chain segment, the defoaming agent has the low surface tension and the excellent defoaming performance of the silicone oil, and further has the water solubility and the dispersibility of the polyether chain segment so as to improve the compatibility and the dispersion uniformity of the defoaming agent in the oil well cement system; secondly, by adding the polyether block modified silicone oil, the dosage of the defoaming agent can be reduced by improving the defoaming efficiency, so that the stability of the defoaming agent in the cement paste is enhanced, and the situation that the defoaming effect is reduced due to non-uniform dispersion is avoided; according to the prepared oil well cement defoaming agent based on dimethyl silicone oil, through innovative component design and an optimized preparation method and process, the defoaming performance, stability and applicability can be comprehensively improved.

Description

Technical Field

[0001] The invention relates to the technical field of defoamers, and in particular to an oil well cement defoamer based on dimethyl silicone oil and a preparation process thereof. Background Art

[0002] In the process of oil exploration and development, oil well cement slurry is an important cementing material, and its performance stability and construction efficiency are directly related to the quality and life of the oil well. However, in the preparation and construction process of oil well cement slurry, due to the introduction of various additives, bubbles generated during the mixing process, and formation gas and other factors, the cement slurry often contains a large number of bubbles, which not only affect the density and uniformity of the cement slurry, but also reduce its compressive strength and sealing performance. In severe cases, it may even lead to cementing failure. Therefore, it is particularly important to develop an efficient, stable and environmentally friendly oil well cement defoamer.

[0003] Traditional oil well cement defoamers mostly use organic silicon, polyether and other compounds as the main components. Although these defoamers have a certain defoaming effect, they still have many shortcomings in practical applications. For example, some defoamers have poor dispersibility in the oil well cement system, making it difficult to quickly and evenly eliminate bubbles; some defoamers have good defoaming effects, but poor environmental performance and will cause pollution to the environment. Therefore, those skilled in the art are in urgent need of developing a new defoamer to solve the above technical problems. Summary of the invention

[0004] Technical issues solved

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides an oil well cement defoamer based on dimethyl silicone oil and a preparation process thereof, which can effectively solve the problems of poor dispersibility and unsatisfactory defoaming performance of the defoamer in the prior art.

[0006] Technical Solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A dimethyl silicone oil-based oil well cement defoamer, the dimethyl silicone oil-based oil well cement defoamer consisting of the following components: polyether block modified silicone oil, fluorine-modified nano silicon dioxide, long-chain alkyl silicone oil, composite dimethyl silicone oil component, composite emulsifier component, hydroxypropyl methylcellulose and deionized water;

[0009] The polyether block modified silicone oil is obtained by reacting a double-terminal hydrogen-containing silicone oil with bisallyl polyoxyethylene polyoxypropylene ether;

[0010] The fluorine-modified nano-silica is prepared by modifying nano-silica with γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride;

[0011] The long-chain alkyl silicone oil is prepared by reacting hydrogen-containing silicone oil and 1-dodecene under the action of a platinum catalyst.

[0012] Furthermore, the preparation steps of the polyether block modified silicone oil are:

[0013] Step 1, weigh 90g of octamethylcyclotetrasiloxane and 100g of tetramethyldihydrogendisiloxane into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen atmosphere, add 2g of concentrated sulfuric acid and continue stirring for 10min, react at a constant temperature for 4h in a water bath at 60°C, cool to room temperature, add solid sodium bicarbonate under stirring to adjust the pH value to 7, filter and place under reduced pressure distillation at a temperature of 68°C for 1h, and the resulting product is a double-terminal hydrogen-containing silicone oil;

[0014] Step 2, weigh 80g of double-terminal hydrogen-containing silicone oil, 85g of bisallyl polyoxyethylene polyoxypropylene ether and 200g of toluene, pour them into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen protection atmosphere, then heat in a water bath to 120°C, drop 1g of isopropanol solution of chloroplatinic acid and react for 3h under a nitrogen protection atmosphere, add 10g of bisallyl polyoxyethylene polyoxypropylene ether, 50g of toluene and 15g of allyl polyoxyethylene polyoxypropylene ether in sequence, react for 2h under negative pressure conditions, and then distill under reduced pressure at a temperature of 65°C for 1h to obtain a polyether block modified silicone oil.

[0015] Furthermore, the stirring speed of the stirring condition in step 1 is 200 r / min, and the isopropanol solution of chloroplatinic acid in step 2 is prepared by mixing chloroplatinic acid and isopropanol in a weight ratio of 1:100 and stirring at a stirring speed of 500 r / min for 10 minutes.

[0016] Furthermore, the preparation steps of the fluorine-modified nano-silica are:

[0017] Step A, adding 4g of nano-silica and 120g of isopropyl ether to a ball mill and milling for 4h, pouring the milled product into a flask and adding 0.7g of γ-aminopropyl triethoxysiloxane, reacting in a water bath at 70°C for 8h and then cooling to 5°C in an ice water bath, the obtained product is recorded as the reaction component;

[0018] Step B: add 1.5 g of perfluorooctanesulfonyl fluoride and 0.5 g of triethylamine to the reaction components, react at a water bath temperature of 65° C. for 2 h, remove the supernatant after centrifugation, wash with petroleum ether three times, and dry to obtain fluorine-modified nano-silica.

[0019] Furthermore, the specific operation of the centrifugal treatment in step B is centrifugation at a speed of 6000 r / min for 5 minutes, and the specific operation of the drying treatment in step B is vacuum drying.

[0020] Furthermore, the preparation method of the long-chain alkyl silicone oil is:

[0021] Add 10g of 1-dodecene into the flask, replace the air with nitrogen at 90°C for 30 minutes, add 0.1g of platinum catalyst and 8g of hydrogenated silicone oil, stir at 90°C for 1h, then raise the temperature to 120°C and continue the reaction for 2h to obtain long-chain alkyl silicone oil.

[0022] Furthermore, the composite dimethyl silicone oil component is prepared by mixing two methyl silicone oils with viscosities of 350 mPa·s and 1000 mPa·s respectively in an equal weight ratio.

[0023] Furthermore, the composite emulsifier component is prepared by mixing emulsifier Tween-10, emulsifier Tween-60 and emulsifier Span-60 in equal weight ratios.

[0024] A preparation process of an oil well cement defoamer based on dimethyl silicone oil, the steps of the preparation process are:

[0025] S1, weigh 20-25 parts by weight of composite dimethyl silicone oil component, 10-15 parts by weight of long-chain alkyl silicone oil, 2-3 parts by weight of hydrophobic fumed silica, 2-3 parts by weight of methyl vinyl MQ silicone resin and 2-3 parts by weight of fluorine-modified nano-silica into a flask, heat and stir to react, then cool to room temperature, and the result is recorded as modified silicone paste component;

[0026] S2. Pour 15-20 parts by weight of the modified silicone paste component, 10-15 parts by weight of the polyether block modified silicone oil and 6-7 parts by weight of the composite emulsifier component into a flask, heat and stir evenly, then drop 25-28 parts by weight of hydroxypropyl methylcellulose, stir evenly again, then add 40-45 parts by weight of deionized water, stir and mix at room temperature, then perform high-speed shear treatment, and the result is an oil well cement defoamer based on dimethyl silicone oil.

[0027] Furthermore, the specific operation of the heating and stirring reaction in S1 is stirring for 3 hours at a stirring speed of 300 r / min under 130°C oil bath conditions, the specific operation of heating and stirring evenly in S2 is stirring for 1 hour at a stirring speed of 500 r / min under 75°C water bath conditions, the dripping rate in S2 is 1 drop / s, the specific operation of stirring evenly again in S2 is stirring for 10 minutes at a stirring speed of 500 r / min, the specific operation of stirring and mixing at room temperature in S2 is stirring for 20 minutes at a stirring speed of 300 r / min, and the specific operation of high-speed shear treatment in S2 is stirring for 5 minutes at a stirring speed of 3000 r / min.

[0028] Beneficial Effects

[0029] The present invention provides an oil well cement defoamer based on dimethyl silicone oil and a preparation process thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention realizes the block combination of silicone oil and polyether chain segments through the reaction of double-terminal hydrogen-containing silicone oil and bisallyl polyoxyethylene polyoxypropylene ether, so that the defoamer has both the low surface tension and excellent defoaming performance of silicone oil and the water solubility and dispersibility of polyether chain segments, thereby improving the compatibility and dispersion uniformity in the oil well cement system; secondly, the addition of polyether block modified silicone oil can reduce the amount of defoamer by improving the defoaming efficiency, thereby enhancing the stability of the defoamer in cement slurry and avoiding the decrease of the defoaming effect due to uneven dispersion.

[0031] 2. The present invention utilizes γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride to modify the surface of nano-silica, and enhances the hydrophobicity and oil resistance of nano-silica by introducing fluorine element, while maintaining the high specific surface area and excellent dispersibility of nano-silica. The addition of fluorine-modified nano-silica can improve the stability and defoaming ability of the defoamer in an oily environment, especially in an oil well cement system, and can effectively prevent the defoamer from failing due to the presence of oil, thereby enhancing the broad-spectrum applicability of the defoamer.

[0032] 3. The present invention prepares silicone oil with a long-chain alkyl structure through the addition reaction of hydrogenated silicone oil and 1-dodecene, which can give the defoamer stronger hydrophobicity and lubricity. The addition of long-chain alkyl silicone oil can enhance the penetration ability and lubrication effect of the defoamer in cement slurry, help reduce the viscosity of cement slurry, and improve fluidity. At the same time, the long-chain structure also increases the durability of the defoamer, thereby extending the defoaming time. The oil well cement defoamer based on dimethyl silicone oil prepared by the present invention can achieve comprehensive improvement in defoaming performance, stability and applicability through innovative component design, optimized preparation method and process, and has significant economic benefits, environmental benefits and application prospects. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention will be further described below in conjunction with the embodiments.

[0035] The sources of some components in the embodiments and comparative examples are as follows:

[0036] Bis-allyl polyoxyethylene polyoxypropylene ether (AAF series), molecular weight 1500, Yangzhou Chenhua Co., Ltd.;

[0037] Allyl polyoxyethylene polyoxypropylene ether (F6), molecular weight 500, Zhejiang Huangma Chemical Co., Ltd.;

[0038] Tetramethyldihydrogendisiloxane, methyl silicone oil, industrial grade, ShinEtsu Co., Ltd., Japan;

[0039] Concentrated sulfuric acid, solid sodium bicarbonate, toluene, octamethylcyclotetrasiloxane (D4), Sinopharm Chemical Reagent Co., Ltd.;

[0040] Nano-silica, γ-aminopropyl triethoxysiloxane, Guangzhou Fogang Fine Chemical Co., Ltd.;

[0041] Perfluorooctanesulfonyl fluoride, industrial grade, Shaowu Huafu Technology Co., Ltd.;

[0042] 1-Dodecene, industrial grade, Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0043] Platinum catalyst, industrial grade, Shenzhen Kejunchi Technology Co., Ltd.;

[0044] Hydrogenated silicone oil, industrial grade, Jiangxi Haiduo Chemical Co., Ltd.;

[0045] Methyl silicone oil (viscosity / 25℃: 350mPa·s), methyl silicone oil (viscosity / 25℃: 1000mPa·s), industrial grade, Tangshan Sanyou Silicon Industry Co., Ltd.;

[0046] Hydrophobic fumed silica, methyl vinyl MQ silicone resin, industrial grade, Jiangxi Xinjiayi New Materials Co., Ltd.;

[0047] Emulsifier Tween-10, Tween-60 and Span-60, industrial grade, Haian Petrochemical Plant, Jiangsu Province;

[0048] Hydroxypropyl methylcellulose, industrial grade, Baoding Huarui Chemical Co., Ltd.

[0049] Example 1

[0050] The present embodiment is a dimethyl silicone oil-based oil well cement defoamer, which is composed of the following components: polyether block modified silicone oil, fluorine-modified nano-silicon dioxide, long-chain alkyl silicone oil, composite dimethyl silicone oil component, composite emulsifier component, hydroxypropyl methylcellulose and deionized water;

[0051] The polyether block modified silicone oil is prepared by reacting a double-terminal hydrogen-containing silicone oil with bisallyl polyoxyethylene polyoxypropylene ether, and the preparation steps are as follows:

[0052] Step 1, weigh 90g of octamethylcyclotetrasiloxane and 100g of tetramethyldihydrogendisiloxane into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen atmosphere, add 2g of concentrated sulfuric acid and continue stirring for 10min, react at a constant temperature for 4h in a water bath at 60°C, cool to room temperature, add solid sodium bicarbonate under a stirring speed of 200r / min to adjust the pH value to 7, filter and place under reduced pressure distillation at a temperature of 68°C for 1h, and the resulting double-terminal hydrogen-containing silicone oil;

[0053] Step 2, weigh 80g of double-terminal hydrogen-containing silicone oil, 85g of bisallyl polyoxyethylene polyoxypropylene ether and 200g of toluene, pour them into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen protection atmosphere, heat in a water bath to 120°C, drop 1g of isopropanol solution of chloroplatinic acid and react for 3h under a nitrogen protection atmosphere, add 10g of bisallyl polyoxyethylene polyoxypropylene ether, 50g of toluene and 15g of allyl polyoxyethylene polyoxypropylene ether in sequence, react for 2h under negative pressure conditions, and then distill under reduced pressure at a temperature of 65°C for 1h to obtain a polyether block modified silicone oil. The isopropanol solution of chloroplatinic acid is prepared by mixing chloroplatinic acid and isopropanol in a weight ratio of 1:100 and stirring at a stirring speed of 500r / min for 10min.

[0054] Fluorine-modified nano-silica is prepared by modifying nano-silica with γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride, and the preparation steps are as follows:

[0055] Step A, adding 4g of nano-silica and 120g of isopropyl ether to a ball mill and milling for 4h, pouring the milled product into a flask and adding 0.7g of γ-aminopropyl triethoxysiloxane, reacting in a water bath at 70°C for 8h and then cooling to 5°C in an ice water bath, the obtained product is recorded as the reaction component;

[0056] Step B: add 1.5 g of perfluorooctanesulfonyl fluoride and 0.5 g of triethylamine to the reaction components, react at a water bath temperature of 65° C. for 2 h, centrifuge at a speed of 6000 r / min for 5 min, remove the supernatant, wash with petroleum ether three times, and vacuum dry to obtain fluorine-modified nano-silica.

[0057] The long-chain alkyl silicone oil is prepared by reacting hydrogenated silicone oil and 1-dodecene under the action of a platinum catalyst, and the preparation method thereof is as follows:

[0058] Add 10g of 1-dodecene into the flask, replace the air with nitrogen at 90°C for 30 minutes, add 0.1g of platinum catalyst and 8g of hydrogenated silicone oil, stir at 90°C for 1h, then raise the temperature to 120°C and continue the reaction for 2h to obtain long-chain alkyl silicone oil.

[0059] The composite dimethyl silicone oil component is prepared by mixing two methyl silicone oils with viscosities of 350 mPa·s and 1000 mPa·s respectively in an equal weight ratio.

[0060] The composite emulsifier component is prepared by mixing emulsifier Tween-10, emulsifier Tween-60 and emulsifier Span-60 in equal weight ratios.

[0061] A preparation process of an oil well cement defoamer based on dimethyl silicone oil, the steps of the preparation process are:

[0062] S1, weigh 20 parts by weight of composite dimethyl silicone oil component, 10 parts by weight of long-chain alkyl silicone oil, 2 parts by weight of hydrophobic fumed silica, 2 parts by weight of methyl vinyl MQ silicone resin and 2 parts by weight of fluorine-modified nano-silica into a flask, stir at 300 r / min for 3 hours in an oil bath at 130°C, and then cool to room temperature. The obtained mixture is recorded as modified silicone paste component;

[0063] S2. Pour 15 parts by weight of modified silicone paste component, 10 parts by weight of polyether block modified silicone oil and 6 parts by weight of composite emulsifier component into a flask, stir at a stirring speed of 500 r / min for 1 hour in a water bath at 75°C, then drop 25 parts by weight of hydroxypropyl methylcellulose, stir at a stirring speed of 500 r / min for 10 minutes, then add 40 parts by weight of deionized water, stir at a stirring speed of 300 r / min for 20 minutes, then stir at a stirring speed of 3000 r / min for 5 minutes for high-speed shear treatment, and the result is an oil well cement defoamer based on dimethyl silicone oil.

[0064] Example 2

[0065] The present embodiment is a dimethyl silicone oil-based oil well cement defoamer, which is composed of the following components: polyether block modified silicone oil, fluorine-modified nano-silicon dioxide, long-chain alkyl silicone oil, composite dimethyl silicone oil component, composite emulsifier component, hydroxypropyl methylcellulose and deionized water;

[0066] The polyether block modified silicone oil is prepared by reacting a double-terminal hydrogen-containing silicone oil with bisallyl polyoxyethylene polyoxypropylene ether, and the preparation steps are as follows:

[0067] Step 1, weigh 90g of octamethylcyclotetrasiloxane and 100g of tetramethyldihydrogendisiloxane into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen atmosphere, add 2g of concentrated sulfuric acid and continue stirring for 10min, react at a constant temperature for 4h in a water bath at 60°C, cool to room temperature, add solid sodium bicarbonate under a stirring speed of 200r / min to adjust the pH value to 7, filter and place under reduced pressure distillation at a temperature of 68°C for 1h, and the resulting double-terminal hydrogen-containing silicone oil;

[0068] Step 2, weigh 80g of double-terminal hydrogen-containing silicone oil, 85g of bisallyl polyoxyethylene polyoxypropylene ether and 200g of toluene, pour them into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen protection atmosphere, heat in a water bath to 120°C, drop 1g of isopropanol solution of chloroplatinic acid and react for 3h under a nitrogen protection atmosphere, add 10g of bisallyl polyoxyethylene polyoxypropylene ether, 50g of toluene and 15g of allyl polyoxyethylene polyoxypropylene ether in sequence, react for 2h under negative pressure conditions, and then distill under reduced pressure at a temperature of 65°C for 1h to obtain a polyether block modified silicone oil. The isopropanol solution of chloroplatinic acid is prepared by mixing chloroplatinic acid and isopropanol in a weight ratio of 1:100 and stirring at a stirring speed of 500r / min for 10min.

[0069] Fluorine-modified nano-silica is prepared by modifying nano-silica with γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride, and the preparation steps are as follows:

[0070] Step A, adding 4g of nano-silica and 120g of isopropyl ether to a ball mill and milling for 4h, pouring the milled product into a flask and adding 0.7g of γ-aminopropyl triethoxysiloxane, reacting in a water bath at 70°C for 8h and then cooling to 5°C in an ice water bath, the obtained product is recorded as the reaction component;

[0071] Step B: add 1.5 g of perfluorooctanesulfonyl fluoride and 0.5 g of triethylamine to the reaction components, react at a water bath temperature of 65° C. for 2 h, centrifuge at a speed of 6000 r / min for 5 min, remove the supernatant, wash with petroleum ether three times, and vacuum dry to obtain fluorine-modified nano-silica.

[0072] The long-chain alkyl silicone oil is prepared by reacting hydrogen-containing silicone oil and 1-dodecene under the action of a platinum catalyst, and the preparation method thereof is as follows:

[0073] Add 10g of 1-dodecene into the flask, replace the air with nitrogen at 90°C for 30 minutes, add 0.1g of platinum catalyst and 8g of hydrogenated silicone oil, stir at 90°C for 1h, then raise the temperature to 120°C and continue the reaction for 2h to obtain long-chain alkyl silicone oil.

[0074] The composite dimethyl silicone oil component is prepared by mixing two methyl silicone oils with viscosities of 350 mPa·s and 1000 mPa·s respectively in an equal weight ratio.

[0075] The composite emulsifier component is prepared by mixing emulsifier Tween-10, emulsifier Tween-60 and emulsifier Span-60 in equal weight ratios.

[0076] A preparation process of an oil well cement defoamer based on dimethyl silicone oil, the steps of the preparation process are:

[0077] S1, weigh 25 parts by weight of composite dimethyl silicone oil component, 15 parts by weight of long-chain alkyl silicone oil, 3 parts by weight of hydrophobic fumed silica, 3 parts by weight of methyl vinyl MQ silicone resin and 3 parts by weight of fluorine-modified nano-silica into a flask, stir at a stirring speed of 300 r / min for 3 hours in an oil bath at 130°C, and then cool to room temperature. The obtained mixture is recorded as a modified silicone paste component;

[0078] S2. Pour 20 parts by weight of modified silicone paste component, 15 parts by weight of polyether block modified silicone oil and 7 parts by weight of composite emulsifier component into a flask, stir at a stirring speed of 500 r / min for 1 hour in a water bath at 75°C, then drop 28 parts by weight of hydroxypropyl methylcellulose, stir at a stirring speed of 500 r / min for 10 minutes, then add 45 parts by weight of deionized water, stir at a stirring speed of 300 r / min for 20 minutes, then stir at a stirring speed of 3000 r / min for 5 minutes for high-speed shear treatment, and the result is an oil well cement defoamer based on dimethyl silicone oil.

[0079] Example 3

[0080] The present embodiment is a dimethyl silicone oil-based oil well cement defoamer, which is composed of the following components: polyether block modified silicone oil, fluorine-modified nano-silicon dioxide, long-chain alkyl silicone oil, composite dimethyl silicone oil component, composite emulsifier component, hydroxypropyl methylcellulose and deionized water;

[0081] The polyether block modified silicone oil is prepared by reacting a double-terminal hydrogen-containing silicone oil with bisallyl polyoxyethylene polyoxypropylene ether, and the preparation steps are as follows:

[0082] Step 1, weigh 90g of octamethylcyclotetrasiloxane and 100g of tetramethyldihydrogendisiloxane into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen atmosphere, add 2g of concentrated sulfuric acid and continue stirring for 10min, react at a constant temperature for 4h in a water bath at 60°C, cool to room temperature, add solid sodium bicarbonate under a stirring speed of 200r / min to adjust the pH value to 7, filter and place under reduced pressure distillation at a temperature of 68°C for 1h, and the resulting double-terminal hydrogen-containing silicone oil;

[0083] Step 2, weigh 80g of double-terminal hydrogen-containing silicone oil, 85g of bisallyl polyoxyethylene polyoxypropylene ether and 200g of toluene, pour them into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen protection atmosphere, heat in a water bath to 120°C, drop 1g of isopropanol solution of chloroplatinic acid and react for 3h under a nitrogen protection atmosphere, add 10g of bisallyl polyoxyethylene polyoxypropylene ether, 50g of toluene and 15g of allyl polyoxyethylene polyoxypropylene ether in sequence, react for 2h under negative pressure conditions, and then distill under reduced pressure at a temperature of 65°C for 1h to obtain a polyether block modified silicone oil. The isopropanol solution of chloroplatinic acid is prepared by mixing chloroplatinic acid and isopropanol in a weight ratio of 1:100 and stirring at a stirring speed of 500r / min for 10min.

[0084] Fluorine-modified nano-silica is prepared by modifying nano-silica with γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride, and the preparation steps are as follows:

[0085] Step A, adding 4g of nano-silica and 120g of isopropyl ether to a ball mill and milling for 4h, pouring the milled product into a flask and adding 0.7g of γ-aminopropyl triethoxysiloxane, reacting in a water bath at 70°C for 8h and then cooling to 5°C in an ice water bath, the obtained product is recorded as the reaction component;

[0086] Step B: add 1.5 g of perfluorooctanesulfonyl fluoride and 0.5 g of triethylamine to the reaction components, react at a water bath temperature of 65° C. for 2 h, centrifuge at a speed of 6000 r / min for 5 min, remove the supernatant, wash with petroleum ether three times, and vacuum dry to obtain fluorine-modified nano-silica.

[0087] The long-chain alkyl silicone oil is prepared by reacting hydrogenated silicone oil and 1-dodecene under the action of a platinum catalyst, and the preparation method thereof is as follows:

[0088] Add 10g of 1-dodecene into the flask, replace the air with nitrogen at 90°C for 30 minutes, add 0.1g of platinum catalyst and 8g of hydrogenated silicone oil, stir at 90°C for 1h, then raise the temperature to 120°C and continue the reaction for 2h to obtain long-chain alkyl silicone oil.

[0089] The composite dimethyl silicone oil component is prepared by mixing two methyl silicone oils with viscosities of 350 mPa·s and 1000 mPa·s respectively in an equal weight ratio.

[0090] The composite emulsifier component is prepared by mixing emulsifier Tween-10, emulsifier Tween-60 and emulsifier Span-60 in equal weight ratios.

[0091] A preparation process of an oil well cement defoamer based on dimethyl silicone oil, the steps of the preparation process are:

[0092] S1, weigh 23 parts by weight of composite dimethyl silicone oil component, 13 parts by weight of long-chain alkyl silicone oil, 2 parts by weight of hydrophobic fumed silica, 3 parts by weight of methyl vinyl MQ silicone resin and 2 parts by weight of fluorine-modified nano-silica into a flask, stir at a stirring speed of 300 r / min for 3 hours in an oil bath at 130°C, and then cool to room temperature. The obtained mixture is recorded as a modified silicone paste component;

[0093] S2. Pour 18 parts by weight of modified silicone paste component, 13 parts by weight of polyether block modified silicone oil and 7 parts by weight of composite emulsifier component into a flask, stir at a stirring speed of 500 r / min for 1 hour in a water bath at 75°C, then drop 26 parts by weight of hydroxypropyl methylcellulose, stir at a stirring speed of 500 r / min for 10 minutes, then add 43 parts by weight of deionized water, stir at a stirring speed of 300 r / min for 20 minutes, then stir at a stirring speed of 3000 r / min for 5 minutes for high-speed shear treatment, and the result is an oil well cement defoamer based on dimethyl silicone oil.

[0094] Comparative Example 1

[0095] The oil well cement defoamer based on dimethyl silicone oil and its preparation process provided in this comparative example are roughly the same as those in Example 1, with the main difference being that in this comparative example, the polyether block modified silicone oil in Example 1 is replaced with dimethyl silicone oil of model cas9006-65-9.

[0096] Comparative Example 2

[0097] The oil well cement defoamer based on dimethyl silicone oil and its preparation process provided in this comparative example are roughly the same as those in Example 1, with the main difference being that in this comparative example, the long-chain alkyl silicone oil in Example 1 is replaced with dimethyl silicone oil of model cas9006-65-9.

[0098] Comparative Example 3

[0099] The oil well cement defoamer based on dimethyl silicone oil and its preparation process provided in this comparative example are roughly the same as those in Example 1, with the main difference being that the fluorine-modified nano-silica in Example 1 is replaced with unmodified nano-silica in this comparative example.

[0100] Performance Testing

[0101] The dimethyl silicone oil-based oil well cement defoamers prepared in Examples 1-3 and Comparative Examples 1-3 are marked as Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3, respectively. Then, the performance of Examples 1-3 and Comparative Examples 1-3 is tested. Taking Example 1 as an example, the specific test method is as follows:

[0102] 1. Weigh 10g of sodium dodecylbenzene sulfonate into a 1L volumetric flask and dilute to volume with deionized water to obtain a 1% mass fraction sodium dodecylbenzene sulfonate aqueous solution, which is the foaming solution.

[0103] 2. Add 100 mL of foaming liquid to a 500 mL measuring cylinder, add 0.01 g of the dimethyl silicone oil-based oil well cement defoamer in Example 1, then insert a glass tube connected to a nitrogen bottle, control the nitrogen flow rate to 500 mL / min, and start a stopwatch to start timing. When the foam rises to the 500 mL mark, stop timing. The obtained time is the foam suppression time;

[0104] 3. After the anti-foaming performance test is completed, continue to introduce nitrogen at a flow rate of 500mL / min. When the foam is higher than the 500mL mark, stop the ventilation and pull out the glass tube. When the foam drops to the 500mL mark, start the stopwatch and stop the timing when the foam is completely eliminated. The obtained time is the defoaming time;

[0105] 4. Measure 15 mL of the dimethyl silicone oil-based oil well cement defoamer in Example 1 into a centrifuge tube, centrifuge at a speed of 3000 r / min for 30 min in a high-speed centrifuge, and observe whether the defoamer is stratified after the centrifugation.

[0106] The data obtained from the above test experiments are recorded in the following table:

[0107]

[0108]

[0109] It can be seen from the data in the above table that the oil well cement defoamer based on dimethyl silicone oil prepared in Examples 1-3 has better defoaming and anti-foaming performance than that of Comparative Examples 1-3, and has better stability, indicating that adding polyether block modified silicone oil, fluorine-modified nano-silica and long-chain alkyl silicone oil to the oil well cement defoamer based on dimethyl silicone oil can play a better role in improving the performance.

[0110] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0111] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oil well cement defoamer based on dimethyl silicone oil, characterized in that: The oil well cement defoamer based on dimethyl silicone oil is composed of the following components: polyether block modified silicone oil, fluorine-modified nano silicon dioxide, long-chain alkyl silicone oil, composite dimethyl silicone oil component, composite emulsifier component, hydroxypropyl methylcellulose and deionized water; The polyether block modified silicone oil is obtained by reacting a double-terminal hydrogen-containing silicone oil with bisallyl polyoxyethylene polyoxypropylene ether; The fluorine-modified nano-silica is prepared by modifying nano-silica with γ-aminopropyl triethoxysiloxane and perfluorooctane sulfonyl fluoride; The long-chain alkyl silicone oil is prepared by reacting hydrogen-containing silicone oil and 1-dodecene under the action of a platinum catalyst.

2. The oil well cement defoamer based on dimethyl silicone oil according to claim 1, characterized in that: The preparation steps of the polyether block modified silicone oil are: Step 1, weigh 90g of octamethylcyclotetrasiloxane and 100g of tetramethyldihydrogendisiloxane into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen atmosphere, add 2g of concentrated sulfuric acid and continue stirring for 10min, react at a constant temperature for 4h in a water bath at 60°C, cool to room temperature, add solid sodium bicarbonate under stirring to adjust the pH value to 7, filter and place under reduced pressure distillation at a temperature of 68°C for 1h, and the resulting product is a double-terminal hydrogen-containing silicone oil; Step 2, weigh 80g of double-terminal hydrogen-containing silicone oil, 85g of bisallyl polyoxyethylene polyoxypropylene ether and 200g of toluene, pour them into a flask, stir at a stirring speed of 200r / min for 10min under a nitrogen protection atmosphere, then heat in a water bath to 120°C, drop 1g of isopropanol solution of chloroplatinic acid and react for 3h under a nitrogen protection atmosphere, add 10g of bisallyl polyoxyethylene polyoxypropylene ether, 50g of toluene and 15g of allyl polyoxyethylene polyoxypropylene ether in sequence, react for 2h under negative pressure conditions, and then distill under reduced pressure at a temperature of 65°C for 1h to obtain a polyether block modified silicone oil.

3. The oil well cement defoamer based on dimethyl silicone oil according to claim 2, characterized in that: The stirring speed of the stirring condition in step 1 is 200 r / min, and the isopropanol solution of chloroplatinic acid in step 2 is prepared by mixing chloroplatinic acid and isopropanol in a weight ratio of 1:100 and stirring at a stirring speed of 500 r / min for 10 minutes.

4. The oil well cement defoamer based on dimethyl silicone oil according to claim 1, characterized in that: The preparation steps of the fluorine-modified nano-silica are: Step A, adding 4g of nano-silica and 120g of isopropyl ether to a ball mill and milling for 4h, pouring the milled product into a flask and adding 0.7g of γ-aminopropyl triethoxysiloxane, reacting in a water bath at 70°C for 8h and then cooling to 5°C in an ice water bath, the obtained product is recorded as the reaction component; Step B: add 1.5 g of perfluorooctanesulfonyl fluoride and 0.5 g of triethylamine to the reaction components, react at a water bath temperature of 65° C. for 2 h, remove the supernatant after centrifugation, wash with petroleum ether three times, and dry to obtain fluorine-modified nano-silica.

5. The oil well cement defoamer based on dimethyl silicone oil according to claim 4, characterized in that: The specific operation of the centrifugal treatment in step B is centrifugation at a speed of 6000 r / min for 5 minutes, and the specific operation of the drying treatment in step B is vacuum drying.

6. The oil well cement defoamer based on dimethyl silicone oil according to claim 1, characterized in that: The preparation method of the long-chain alkyl silicone oil is: Add 10g of 1-dodecene into the flask, replace the air with nitrogen at 90°C for 30 minutes, add 0.1g of platinum catalyst and 8g of hydrogenated silicone oil, stir at 90°C for 1h, then raise the temperature to 120°C and continue the reaction for 2h to obtain long-chain alkyl silicone oil.

7. The oil well cement defoamer based on dimethyl silicone oil according to claim 1, characterized in that: The composite dimethyl silicone oil component is prepared by mixing two methyl silicone oils with viscosities of 350 mPa·s and 1000 mPa·s respectively in an equal weight ratio.

8. The oil well cement defoamer based on dimethyl silicone oil according to claim 1, characterized in that: The composite emulsifier component is prepared by mixing emulsifier Tween-10, emulsifier Tween-60 and emulsifier Span-60 in equal weight ratios.

9. A process for preparing an oil well cement defoamer based on dimethyl silicone oil according to any one of claims 1 to 8, characterized in that: The steps of the preparation process are: S1, weigh 20-25 parts by weight of composite dimethyl silicone oil component, 10-15 parts by weight of long-chain alkyl silicone oil, 2-3 parts by weight of hydrophobic fumed silica, 2-3 parts by weight of methyl vinyl MQ silicone resin and 2-3 parts by weight of fluorine-modified nano-silica into a flask, heat and stir to react, then cool to room temperature, and the result is recorded as modified silicone paste component; S2. Pour 15-20 parts by weight of the modified silicone paste component, 10-15 parts by weight of the polyether block modified silicone oil and 6-7 parts by weight of the composite emulsifier component into a flask, heat and stir evenly, then drop 25-28 parts by weight of hydroxypropyl methylcellulose, stir evenly again, then add 40-45 parts by weight of deionized water, stir and mix at room temperature, then perform high-speed shear treatment, and the result is an oil well cement defoamer based on dimethyl silicone oil.

10. The preparation process of a dimethyl silicone oil-based oil well cement defoamer according to claim 9, characterized in that: The specific operation of the heating and stirring reaction in S1 is stirring for 3 hours at a stirring speed of 300 r / min under 130°C oil bath conditions, the specific operation of heating and stirring evenly in S2 is stirring for 1 hour at a stirring speed of 500 r / min under 75°C water bath conditions, the dripping rate in S2 is 1 drop / s, the specific operation of stirring evenly again in S2 is stirring for 10 minutes at a stirring speed of 500 r / min, the specific operation of stirring and mixing at room temperature in S2 is stirring for 20 minutes at a stirring speed of 300 r / min, and the specific operation of high-speed shear treatment in S2 is stirring for 5 minutes at a stirring speed of 3000 r / min.

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