Temperature-resistant solid corrosion inhibitor for ultra-deep well and preparation method thereof

Abstract

The application discloses a preparation method of a temperature-resistant solid corrosion inhibitor for super-deep wells, which comprises the following steps: uniformly mixing a synergist and a main corrosion inhibitor agent at 80-100 DEG C, and keeping warm to obtain a first intermediate; uniformly mixing the first intermediate and a surfactant to obtain a second intermediate; uniformly mixing the second intermediate, a binder, a toughening agent and a filler to obtain a third intermediate; and preparing the third intermediate into particles to obtain the corrosion inhibitor. The corrosion inhibitor prepared by the method has the characteristics of high temperature resistance, stable performance and excellent corrosion inhibition effect, can be used as a broad-spectrum corrosion inhibitor for oil and gas field exploitation, and overcomes the shortcomings of the existing corrosion inhibitors; the corrosion inhibitor is suitable for not only the crude oil medium in oil wells and the gas medium environment in gas wells, but also the water medium environment in water injection wells in oil fields, and has good corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of corrosion inhibitor technology, specifically to a high-temperature resistant solid corrosion inhibitor for ultra-deep wells and its preparation method. Background Technology

[0002] With the continuous exploitation and production of oil and gas fields, the overall water cut of oil and gas wells continues to rise, and the produced fluids contain a large amount of corrosive media, leading to intensified corrosion of downhole production tubing. Currently, injecting liquid corrosion inhibitors is a common anti-corrosion measure in oil fields. However, the injection of liquid corrosion inhibitors requires equipment such as dosing pumps, and the liquid corrosion inhibitors tend to adhere to the tubing walls, resulting in high consumption. Furthermore, intermittent injection leads to uneven dosing, affecting the corrosion inhibition effect. In addition, the use of liquid corrosion inhibitors presents some inconveniences for wells with high water production, high water levels, remote wells, and wells with packers. Moreover, while liquid corrosion inhibitors can exert their inhibitory effect at high temperatures, the effective protection time is short. When the operating environment exceeds 60℃, the effectiveness of liquid corrosion inhibitors generally does not exceed 7 days, after which the inhibitory effect decreases significantly. Therefore, in actual oil and gas well operations, multiple or continuous injections of corrosion inhibitors are often required, which not only increases the construction difficulty of oil and gas well operations but also raises production costs.

[0003] Therefore, how to provide a corrosion inhibitor that can provide protection for a longer time at high temperatures has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the aforementioned technical problems, the first aspect of this invention provides a method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor, comprising the following steps:

[0005] (1) At 80-100℃, the synergist and the main corrosion inhibitor are mixed evenly and kept warm to obtain the first intermediate;

[0006] (2) Mix the first intermediate with the surfactant until homogeneous to obtain the second intermediate;

[0007] (3) After the second intermediate is mixed evenly with the adhesive, toughening agent and filler, the third intermediate is obtained;

[0008] (4) The third intermediate is prepared into particles.

[0009] As a preferred technical solution of the present invention, the synergist in step (1) is selected from either hexamethylenetetramine or sodium nitrite.

[0010] As a preferred technical solution of the present invention, the surfactant in step (2) is selected from any one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0011] As a preferred technical solution of the present invention, the adhesive in step (3) is selected from any one of petroleum resin and polyvinyl alcohol.

[0012] As a preferred embodiment of the present invention, the degree of polymerization of the polyvinyl alcohol is 2000-2400 and the degree of alcoholysis is 88-100%.

[0013] As a preferred embodiment of the present invention, the polyvinyl alcohol comprises PVA20-99 and PVA24-99.

[0014] As a preferred embodiment of the present invention, the weight ratio of PVA20-99 to PVA24-99 is 1:(1.2 to 1.4).

[0015] As a preferred technical solution of the present invention, the toughening agent in step (3) is selected from one or more combinations of polycarbonate, polyether thermoplastic polyurethane elastomer, polyvinyl acetate emulsion, EVA emulsion, and acrylic emulsion.

[0016] As a preferred technical solution of the present invention, the filler in step (3) is selected from one or more combinations of barium sulfate, fumed silica, calcium carbonate, and calcium silicate.

[0017] A second aspect of the present invention provides a temperature-resistant ultra-deep well solid corrosion inhibitor prepared according to the method.

[0018] Beneficial effects: This invention provides a method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor. The corrosion inhibitor prepared by this method has the characteristics of high temperature resistance, stable performance, and excellent corrosion inhibition effect. It can be used as a broad-spectrum corrosion inhibitor for oil and gas field development, overcoming the shortcomings of existing corrosion inhibitors. This corrosion inhibitor is not only suitable for crude oil media in oil wells and gas media environments in gas wells, but also suitable for water media environments in water injection wells in oil fields, and has a good anti-corrosion effect. Detailed Implementation

[0019] To address the aforementioned technical problems, the first aspect of this invention provides a method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor, comprising the following steps:

[0020] (1) At 80-100℃, the synergist and the main corrosion inhibitor are mixed evenly and kept warm to obtain the first intermediate;

[0021] (2) Mix the first intermediate with the surfactant until homogeneous to obtain the second intermediate;

[0022] (3) After the second intermediate is mixed evenly with the adhesive, toughening agent and filler, the third intermediate is obtained;

[0023] (4) The third intermediate is prepared into particles.

[0024] <Enhancing Agent>

[0025] The synergist described in this invention is selected from either hexamethylenetetramine or sodium nitrite.

[0026] In a preferred embodiment, the synergist is sodium nitrite.

[0027] <Corrosion Inhibitor Main Component>

[0028] The main component of the corrosion inhibitor described in this invention is selected from one or a combination of several of the following: imidazoline quaternary ammonium salt corrosion inhibitors, glucosamide corrosion inhibitors, Mannich base corrosion inhibitors, and quinoline quaternary ammonium salt corrosion inhibitors.

[0029] In a preferred embodiment, the main component of the corrosion inhibitor is an imidazoline quaternary ammonium salt corrosion inhibitor.

[0030] In a more preferred embodiment, the imidazoline quaternary ammonium salt corrosion inhibitor is a fluorinated imidazoline quaternary ammonium salt corrosion inhibitor.

[0031] In a more preferred embodiment, the raw materials for preparing the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor include organic acids and organic polyamines.

[0032] In a more preferred embodiment, the molar ratio of the organic acid to the organic polyamine is 1:(1 to 1.8); more preferably, the molar ratio of the organic acid to the organic polyamine is 1:1.4.

[0033] In a more preferred embodiment, the organic acid is selected from one or more combinations of oleic acid, caprylic acid, and perfluoroacetic acid; the organic polyamine is selected from one or more combinations of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, aminoethylamino)-3-isobutyldimethylmethoxysilane, and N-aminoethyl-3-aminopropylmethyldimethoxysilane.

[0034] In a more preferred embodiment, the organic acid is perfluoroacetic acid; and the organic polyamine is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0035] The preparation steps of the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor are as follows: 0.16 mol of perfluoroacetic acid and 50 mL of toluene are added to a 50 mL three-necked flask, with activated alumina as the catalyst and toluene as the dehydrating agent. The refluxed water is used, and the temperature is raised to 160 °C. N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is slowly added to the flask using a dropping funnel, and the reaction is maintained at a constant temperature for 4 h. The temperature is then raised to 200 °C and maintained at a constant temperature for 4 h. The temperature is lowered to 80 °C, and 20 mL of bromododecane is slowly added to the flask, and the reaction is maintained at a constant temperature for 5 h. After the reaction is complete, acetone is added to remove impurities, and the mixture is then vacuum rotary evaporated to obtain the final product.

[0036] This invention modifies imidazoline quaternary ammonium salt corrosion inhibitors, selecting perfluoroacetic acid and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane as raw materials. The resulting corrosion inhibitor can form a dense protective film on the metal surface, exhibiting excellent high-temperature resistance and a corrosion inhibition rate of over 90%.

[0037] <surfactants>

[0038] The surfactant described in this invention is selected from any one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0039] In a preferred embodiment, the surfactant is a fatty alcohol polyoxyethylene ether.

[0040] In a more preferred embodiment, the fatty alcohol polyoxyethylene ether is selected from one or a combination of MOA-3, MOA-4, MOA-5, and MOA-7.

[0041] In a more preferred embodiment, the fatty alcohol polyoxyethylene ether is MOA-4, purchased from Nantong Derek Chemical Co., Ltd.

[0042] <Adhesive>

[0043] The adhesive described in this invention is selected from any one of petroleum resin and polyvinyl alcohol.

[0044] In a preferred embodiment, the adhesive is polyvinyl alcohol.

[0045] In a more preferred embodiment, the degree of polymerization of the polyvinyl alcohol is 2000-2400 and the degree of hydrolysis is 88-100%.

[0046] In a more preferred embodiment, the polyvinyl alcohol comprises PVA20-99 and PVA24-99.

[0047] In a more preferred embodiment, the weight ratio of PVA20-99 to PVA24-99 is 1:(1.2 to 1.4); more preferably, the weight ratio of PVA20-99 to PVA24-99 is 1:1.3.

[0048] In a more preferred embodiment, the PVA20-99 and PVA24-99 were purchased from Shanghai Yingjia Industrial Development Co., Ltd.

[0049] Toughening agent

[0050] The toughening agent described in this invention is selected from one or a combination of polycarbonate, polyether thermoplastic polyurethane elastomer, polyvinyl acetate emulsion, EVA emulsion, and acrylic emulsion.

[0051] In a preferred embodiment, the toughening agent is an acrylic emulsion.

[0052] In a more preferred embodiment, the acrylic emulsion was purchased from Shenzhen Jinhua Shengxin Materials Co., Ltd. as JJ699.

[0053] The present invention selects polyvinyl alcohol containing PVA20-99 and PVA24-99 and adjusts the weight ratio of PVA20-99 and PVA24-99 to 1:(1.2~1.4), which is easy to process and can interact with other components of the system to prepare a relatively stable corrosion inhibitor. It is not only suitable for crude oil media in oil wells and gas media environments in gas wells, but also suitable for water media environments in water injection wells in oil fields, and can bring excellent corrosion resistance.

[0054] <filler>

[0055] The filler described in this invention is selected from one or a combination of barium sulfate, fumed silica, calcium carbonate, and calcium silicate.

[0056] In a preferred embodiment, the filler is calcium carbonate.

[0057] In a more preferred embodiment, the preparation method of the temperature-resistant ultra-deep well solid corrosion inhibitor includes the following steps:

[0058] (1) At 80-100℃, the synergist and the main corrosion inhibitor are mixed evenly and kept warm for 20-40 minutes to obtain the first intermediate;

[0059] (2) Mix the first intermediate with the surfactant until homogeneous to obtain the second intermediate;

[0060] (3) After the second intermediate is mixed evenly with the adhesive, toughening agent and filler, the third intermediate is obtained;

[0061] (4) Place the third intermediate in a granulator and granulate it to obtain the final product.

[0062] A second aspect of the present invention provides a temperature-resistant ultra-deep well solid corrosion inhibitor prepared according to the method.

[0063] Example

[0064] Example 1

[0065] Example 1 of the present invention provides a high-temperature resistant ultra-deep well solid corrosion inhibitor, the preparation method of which includes the following steps:

[0066] (1) At 90℃, the synergist and the main corrosion inhibitor are mixed evenly and kept warm for 30 minutes to obtain the first intermediate;

[0067] (2) Mix the first intermediate with the surfactant until homogeneous to obtain the second intermediate;

[0068] (3) After the second intermediate is mixed evenly with the adhesive, toughening agent and filler, the third intermediate is obtained;

[0069] (4) Place the third intermediate in a granulator and granulate it to obtain the final product.

[0070] The synergist is sodium nitrite.

[0071] The main component of the corrosion inhibitor is a fluorinated imidazoline quaternary ammonium salt corrosion inhibitor; the raw materials for preparing the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor include organic acids and organic polyamines; the molar ratio of the organic acid and the organic polyamine is 1:1.4; the organic acid is perfluoroacetic acid; and the organic polyamine is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0072] The preparation steps of the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor are as follows: 0.16 mol of perfluoroacetic acid and 50 mL of toluene are added to a 50 mL three-necked flask, with activated alumina as the catalyst and toluene as the dehydrating agent. The refluxed water is used, and the temperature is raised to 160 °C. N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is slowly added to the flask using a dropping funnel, and the reaction is maintained at a constant temperature for 4 h. The temperature is then raised to 200 °C and maintained at a constant temperature for 4 h. The temperature is lowered to 80 °C, and 20 mL of bromododecane is slowly added to the flask, and the reaction is maintained at a constant temperature for 5 h. After the reaction is complete, acetone is added to remove impurities, and the mixture is then vacuum rotary evaporated to obtain the final product.

[0073] The surfactant is a fatty alcohol polyoxyethylene ether; the fatty alcohol polyoxyethylene ether is MOA-4, purchased from Nantong Derek Chemical Co., Ltd.

[0074] The adhesive is polyvinyl alcohol; the polyvinyl alcohol includes PVA20-99 and PVA24-99; the weight ratio of PVA20-99 and PVA24-99 is 1:1.3; the PVA20-99 and PVA24-99 were purchased from Shanghai Yingjia Industrial Development Co., Ltd.

[0075] The toughening agent is an acrylic emulsion, purchased from Shenzhen Jinhua Shengxin Material Co., Ltd. as JJ699.

[0076] The filler is calcium carbonate.

[0077] Comparative Example 1

[0078] Comparative Example 1 of the present invention provides a solid corrosion inhibitor, the specific implementation of which is the same as that of Example 1, except that the organic acid is oleic acid.

[0079] Comparative Example 2

[0080] Comparative Example 2 of the present invention provides a solid corrosion inhibitor, the specific implementation of which is the same as that of Example 1, except that the organic polyamine is diethylenetriamine.

[0081] Comparative Example 3

[0082] Comparative Example 3 of the present invention provides a solid corrosion inhibitor, the specific implementation of which is the same as that of Example 1, except that the weight ratio of PVA20-99 and PVA24-99 is 1:0.9.

[0083] Comparative Example 4

[0084] Comparative Example 4 of the present invention provides a solid corrosion inhibitor, the specific implementation of which is the same as that of Example 1, except that it does not contain PVA20-99.

[0085] Comparative Example 5

[0086] Comparative Example 5 of the present invention provides a solid corrosion inhibitor, the specific implementation of which is the same as that of Example 1, except that it does not contain PVA24-99.

[0087] Performance Evaluation

[0088] The weight loss test of the test piece was conducted according to the national standard GB / 10124-88 "Metallic Materials Laboratory Uniform Corrosion Test Method" and the Chinese petroleum industry standard SY / T 5273-2000 "Evaluation Method of Corrosion Inhibitors for Petroleum Produced Water". The test solution was oilfield wastewater from deep wells, with a volume of 1L. The test piece was made of N80 steel, the test temperature was 140℃, and the amount of corrosion inhibitor added was 1g. The weighed test pieces were respectively immersed in the test solutions with and without corrosion inhibitor. After immersion for 1 day and 2 weeks, the test pieces were removed and their mass was measured, and the corrosion inhibition rate was recorded.

[0089] Table 1

[0090]

[0091] As can be seen from the data in the table above, the corrosion inhibitor prepared by this invention does not decompose or volatilize rapidly at temperatures as high as 140°C, and can form a dense protective film on its surface. When the specimen is corroded at 140°C for 2 weeks, it also has a good corrosion inhibition rate, which can reach 90%.

Claims

1. A method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor, characterized in that, Includes the following steps: (1) At 80~100℃, the synergist and the main corrosion inhibitor are mixed evenly and kept warm to obtain the first intermediate; (2) Mix the first intermediate with the surfactant until homogeneous to obtain the second intermediate; (3) After the second intermediate is mixed evenly with the adhesive, toughening agent and filler, the third intermediate is obtained; (4) The third intermediate is prepared into particles to obtain the final product; The main component of the corrosion inhibitor is a fluorinated imidazoline quaternary ammonium salt corrosion inhibitor. The raw materials for preparing the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor include organic acid and organic polyamine, with a molar ratio of organic acid to organic polyamine of 1:1.

4. The organic acid is perfluoroacetic acid, and the organic polyamine is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The adhesive is polyvinyl alcohol, which includes PVA20-99 and PVA24-99, with a weight ratio of PVA20-99 to PVA24-99 of 1:1.

3. The preparation steps of the fluorinated imidazoline quaternary ammonium salt corrosion inhibitor are as follows: 0.16 mol of perfluoroacetic acid and 50 mL of toluene are added to a 50 mL three-necked flask, with activated alumina as the catalyst and toluene as the dehydrating agent. The condensate is refluxed and the temperature is raised to 160 °C. N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is slowly added to the flask using a dropping funnel and reacted at a constant temperature for 4 h. The temperature is then raised to 200 °C and reacted at a constant temperature for 4 h. The temperature is lowered to 80 °C and 20 mL of bromododecane is slowly added to the flask and reacted at a constant temperature for 5 h. After the reaction is completed, acetone is added to remove impurities and then the mixture is vacuum rotary evaporated to obtain the final product.

2. The method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor according to claim 1, characterized in that, The synergist in step (1) is selected from either hexamethylenetetramine or sodium nitrite.

3. The method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor according to claim 1, characterized in that, The surfactant used in step (2) is selected from either fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether.

4. The method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor according to claim 1, characterized in that, The degree of polymerization of the polyvinyl alcohol is 2000~2400, and the degree of alcoholysis is 88~100%.

5. The method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor according to claim 1, characterized in that, The toughening agent in step (3) is selected from one or more combinations of polycarbonate, polyether thermoplastic polyurethane elastomer, polyvinyl acetate emulsion, EVA emulsion, and acrylic emulsion.

6. The method for preparing a high-temperature resistant ultra-deep well solid corrosion inhibitor according to claim 1, characterized in that, The filler in step (3) is selected from one or a combination of barium sulfate, fumed silica, calcium carbonate, and calcium silicate.

7. A high-temperature resistant solid corrosion inhibitor for ultra-deep wells, characterized in that, The heat-resistant ultra-deep well solid corrosion inhibitor is a heat-resistant ultra-deep well solid corrosion inhibitor prepared by the method described in any one of claims 1 to 6.

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