Corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields and preparation method thereof

Abstract

The invention discloses a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields and a preparation method thereof, and belongs to the technical field of oilfield chemistry. The corrosion inhibitor is prepared from the following components in parts by weight: 35 to 50 parts of mercaptopropyl indole quaternary ammonium salt, 25 to 40 parts of a surfactant and 20 to 30 parts of an alcoholic solution, the mercaptopropyl indole quaternary ammonium salt is prepared from 35 to 50 parts of mercaptopropyl indole compound and 50 to 65 parts of benzyl chloride. The preparation method of the corrosion inhibitor comprises the following steps: preparing a mercaptopropyl indole compound, and stirring the mercaptopropyl indole compound and benzyl chloride at a set temperature for a set time to obtain mercaptopropyl indole quaternary ammonium salt; the mercaptopropyl indole quaternary ammonium salt, the surfactant and the alcoholic solution are stirred and mixed, and the hydrogen sulfide corrosion inhibitor is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemistry, and in particular relates to a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields and a preparation method thereof. Background Art

[0002] With the emergence of oil and gas fields containing hydrogen sulfide corrosive media, mining equipment will suffer serious corrosion in such acidic media containing hydrogen sulfide. The highly corrosive hydrogen sulfide gas not only causes damage to mining pipelines and equipment, resulting in economic losses, but also forms an explosive mixture when hydrogen sulfide leaks due to its flammable and explosive properties. It can cause combustion and explosion when exposed to open flames and high heat, and react violently with concentrated nitric acid, fuming sulfuric acid or other strong oxidants, causing explosions and serious safety accidents and environmental damage. Therefore, how to solve the corrosion hazards of hydrogen sulfide has become a major technical problem in the mining process of high-sulfur oil and gas fields.

[0003] For the corrosion problem in oil and gas fields, adding corrosion inhibitors is the most common, simple and quick method. Corrosion inhibitor molecules with polar groups provide protection for metals by adsorbing on the metal surface to form a film. However, the most widely used imidazoline corrosion inhibitors in oil and gas fields are not very effective in inhibiting hydrogen sulfide corrosion. Therefore, it is of great significance to prepare a corrosion inhibitor that can effectively solve hydrogen sulfide corrosion in the exploitation of high-sulfur oil and gas fields. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields and a preparation method thereof. The provided corrosion inhibitor can effectively solve the technical problem of hydrogen sulfide corrosion in the exploitation of high-sulfur oil and gas fields.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields, which comprises, by weight, 35 to 50 parts of mercaptopropyl indole quaternary ammonium salt, 25 to 40 parts of surfactant and 20 to 30 parts of alcohol solution;

[0007] The mercaptopropyl indole quaternary ammonium salt has the structural formula (I) as follows:

[0008]

[0009] In a specific implementation process, the mercaptopropyl indole quaternary ammonium salt includes 35 to 50 parts of mercaptopropyl indole compound and 50 to 65 parts of benzyl chloride;

[0010] The mercaptopropyl indole compound has the structural formula (II):

[0011]

[0012] In a specific implementation process, the surfactant is at least one of OP-10, AEO-10, NP-10 and TX-10.

[0013] In a specific implementation process, the alcohol solution is one of propanol, isopropanol and butanol.

[0014] The present invention also provides a method for preparing a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields according to any one of the above, comprising the following steps:

[0015] S1: preparing a mercaptopropyl indole compound, stirring the mercaptopropyl indole compound and benzyl chloride at a set temperature for a set time to obtain a mercaptopropyl indole quaternary ammonium salt;

[0016] S2: Stir the mercaptopropyl indole quaternary ammonium salt, the surfactant and the alcohol solution until mixed to obtain a hydrogen sulfide corrosion inhibitor.

[0017] In the specific implementation process, the steps of preparing the mercaptopropyl indole compound are as follows:

[0018] Indole and 3-chloro-1-propanethiol are used as raw materials to undergo chlorination reaction in an alkaline environment to generate mercaptopropyl indole compounds.

[0019] In a specific implementation process, the mass ratio of indole to 3-chloro-1-propanethiol is (1-1.2):1.

[0020] In a specific implementation process, the alkaline environment is an environment in which the pH value of the solution is adjusted to 10 by sodium hydroxide.

[0021] In the specific implementation process, the reaction time of the chlorination reaction is 10 hours, and the reaction temperature of the chlorination reaction is 90°C.

[0022] In the specific implementation process, in S1, the set temperature is 90-120° C.; the set time is 12 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention provides a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields. A mercaptopropyl indole quaternary ammonium salt compound prepared by a quaternization reaction of a mercaptopropyl indole compound is used as an important component of the hydrogen sulfide corrosion inhibitor. The corrosion inhibitor prepared by the quaternization of the mercaptopropyl indole compound can effectively inhibit the corrosion of hydrogen sulfide. In addition, the corrosion inhibitor has a small amount of feed in actual use, a significant corrosion inhibition effect, and good resistance to high-temperature hydrogen sulfide corrosion.

[0025] The above-mentioned corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields can be used in a process environment containing 0.1 MPa to 1 MPa hydrogen sulfide partial pressure at room temperature (such as 25°C) to 80°C, and the hydrogen sulfide corrosion inhibitor of the present invention can be directly added to the corrosive medium. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0028] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0029] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0030] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0032] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0033] The invention provides a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields and a preparation method thereof.

[0034] The first aspect of the present invention provides a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields, which comprises, by weight, 35 to 50 parts of mercaptopropyl indole quaternary ammonium salt, 25 to 40 parts of surfactant and 20 to 30 parts of alcohol solution; the mercaptopropyl indole quaternary ammonium salt comprises 35 to 50 parts of mercaptopropyl indole compound and 50 to 65 parts of benzyl chloride;

[0035] The mercaptopropyl indole quaternary ammonium salt has the structural formula (I) as follows:

[0036]

[0037] The mercaptopropyl indole compound has the structural formula (II):

[0038]

[0039] In a specific implementation process, the surfactant is at least one of OP-10, AEO-10, NP-10 and TX-10; and the alcohol solution is one of propanol, isopropanol and butanol.

[0040] The second aspect of the present invention provides a method for preparing a corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields, comprising the following steps:

[0041] S1: using indole and 3-chloro-1-propanethiol in a mass ratio of (1-1.2):1 as raw materials, carrying out chlorination reaction in an alkaline environment at 90°C for 10 hours to prepare a mercaptopropyl indole compound, stirring the mercaptopropyl indole compound and benzyl chloride at 90-120°C for 12 hours to obtain a mercaptopropyl indole quaternary ammonium salt; wherein the alkaline environment is an environment in which the pH value of the solution is adjusted to 10 by sodium hydroxide;

[0042] S2: Stir the mercaptopropyl indole quaternary ammonium salt, the surfactant and the alcohol solution until mixed to obtain a hydrogen sulfide corrosion inhibitor.

[0043] The invention improves the preparation method of the indole functional group modification and mercaptopropyl indole quaternary ammonium salt compound and provides a corrosion inhibitor using the mercaptopropyl indole quaternary ammonium salt compound as the main body and a preparation method thereof for inhibiting hydrogen sulfide corrosion, thereby effectively solving the problem that conventional imidazoline corrosion inhibitors have an unsatisfactory inhibitory effect on hydrogen sulfide corrosion. The hydrogen sulfide corrosion inhibitor prepared by quaternization of the compound through functional group substitution can effectively inhibit the corrosion of hydrogen sulfide to metal pipelines during oil and gas production.

[0044] Specifically, improvements are made by branching the thiol groups on the indole molecule, quaternizing the mercaptopropyl indole, and applying the mercaptopropyl indole quaternary ammonium salt compound and its application method (such as the ratio of the mercaptopropyl indole compound and other raw materials in the corrosion inhibitor synthesis process, the synthesis temperature conditions, and the selection of the dispersant for the corrosion inhibitor).

[0045] Example 1

[0046] 50 g of indole and 50 g of 3-chloro-1-propanethiol were added to a three-necked flask, and stirring was started. The pH of the solution was adjusted to 10 with sodium hydroxide, and the temperature was raised to 90° C. The temperature was maintained for 10 hours to obtain a mercaptopropyl indole compound.

[0047] 50 g of the mercaptopropyl indole compound prepared above and 50 g of benzyl chloride were added to a three-necked flask, and the mixture was stirred and mixed at 100° C. for 12 hours to obtain mercaptopropyl indole quaternary ammonium salt.

[0048] In a three-necked flask, 40 grams of the prepared mercaptopropyl indole quaternary ammonium salt, 30 grams of OP-10, and 30 grams of isopropanol were added and mixed to obtain 100 grams of hydrogen sulfide corrosion inhibitor.

[0049] Corrosion inhibition performance evaluation:

[0050] The corrosion inhibition performance was evaluated according to the industry standard SY / T 5273-2000.

[0051] Table 1 shows the comparative evaluation results of the corrosion inhibitor prepared in Example 1 and commercially available oleic acid-based imidazoline.

[0052] Table 1

[0053]

[0054] It can be seen from the test data in Table 1 that, under the same conditions, the corrosion inhibition performance of the corrosion inhibitor of the present invention in corrosive media is far superior to that of commercially available oleic acid imidazoline, and the corrosion inhibitor of the present invention can meet the industry requirement that the corrosion rate is not greater than 0.076 mm / a.

[0055] Example 2

[0056] 50 g of indole and 45 g of 3-chloro-1-propanethiol were added to a three-necked flask, and stirring was started. The pH of the solution system was adjusted to 10 with sodium hydroxide, and the temperature was raised to 90° C. and the temperature was maintained for 10 hours to obtain a mercaptopropyl indole compound.

[0057] 40 g of the mercaptopropyl indole compound prepared above and 60 g of benzyl chloride were added to a three-necked flask, and the mixture was stirred and mixed at 120° C. for 12 hours to obtain mercaptopropyl indole quaternary ammonium salt.

[0058] In a three-necked flask, 50 grams of the mercaptopropyl indole quaternary ammonium salt prepared above, 30 grams of OP-10, and 20 grams of isopropanol were added and mixed to obtain 100 grams of hydrogen sulfide corrosion inhibitor.

[0059] Corrosion inhibition performance evaluation:

[0060] The corrosion inhibition performance was evaluated according to the industry standard SY / T 5273-2000.

[0061] Table 2 shows the comparative evaluation results of the corrosion inhibitor prepared in Example 2 and commercially available imidazoline phosphate.

[0062] Table 2

[0063]

[0064] It can be seen from the test data in Table 2 that, under the same conditions, the corrosion inhibition performance of the corrosion inhibitor of the present invention in hydrogen sulfide corrosive media is much better than that of commercially available imidazoline phosphate products, and the corrosion inhibitor of the present invention can meet the industry requirement that the corrosion rate is not greater than 0.076 mm / a.

[0065] Example 3

[0066] 50 g of indole and 48 g of 3-chloro-1-propanethiol were added to a three-necked flask, and stirring was started. The pH of the solution was adjusted to 10 with sodium hydroxide, and the temperature was raised to 90° C. and the temperature was maintained for 12 hours to obtain a mercaptopropyl indole compound.

[0067] 45 g of the mercaptopropyl indole compound prepared above and 55 g of benzyl chloride were added to a three-necked flask, and the mixture was stirred and mixed at 100° C. for 12 hours to obtain mercaptopropyl indole quaternary ammonium salt.

[0068] 35 g of the mercaptopropyl indole quaternary ammonium salt prepared above, 40 g of OP-10 and 25 g of isopropanol were added to a three-necked flask and mixed to obtain 100 g of hydrogen sulfide corrosion inhibitor.

[0069] Corrosion inhibition performance evaluation:

[0070] The corrosion inhibition performance was evaluated according to the industry standard SY / T 5273-2000.

[0071] Table 3 shows the comparative evaluation results of the corrosion inhibitor prepared in Example 3 and commercially available thiourea-based imidazoline.

[0072] Table 3

[0073]

[0074] It can be seen from the test data in Table 3 that under the same conditions, the corrosion inhibition performance of the corrosion inhibitor of the present invention in a hydrogen sulfide-containing medium environment is far superior to that of the commercially available thiourea-based imidazoline product. At the same time, the corrosion inhibitor of the present invention can meet the industry requirement that the corrosion rate is not greater than 0.076 mm / a.

[0075] Example 4

[0076] 50 g of indole and 49 g of 3-chloro-1-propanethiol were added to a three-necked flask, and stirring was started. The pH of the solution system was adjusted to 10 with sodium hydroxide, and the temperature was raised to 90° C. and the temperature was maintained for 10 hours to obtain a mercaptopropyl indole compound.

[0077] 35 g of the mercaptopropyl indole compound prepared above and 65 g of benzyl chloride were added to a three-necked flask, and the mixture was stirred and mixed at 120° C. for 12 hours to obtain mercaptopropyl indole quaternary ammonium salt.

[0078] In a three-necked flask, 50 grams of the mercaptopropyl indole quaternary ammonium salt prepared above, 25 grams of OP-10, and 25 grams of isopropanol were added and mixed to obtain 100 grams of hydrogen sulfide corrosion inhibitor.

[0079] In the above embodiments, the surfactant may be at least one of OP-10, AEO-10, NP-10 and TX-10; the alcohol solution may be at least one of propanol, isopropanol and butanol.

[0080] The corrosion inhibitor for inhibiting hydrogen sulfide corrosion provided by the present invention is obtained by quaternizing raw materials such as mercaptopropyl indole compounds and benzyl chloride, wherein the mercaptopropyl indole quaternary ammonium salt compound is an important component of the corrosion inhibitor to exert its corrosion inhibition effect; the corrosion inhibitor has a small amount of material input during actual use, a significant corrosion inhibition effect, and good resistance to high-temperature hydrogen sulfide corrosion.

[0081] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields, It is characterized in that The composition comprises, by weight, 35 to 50 parts of mercaptopropyl indole quaternary ammonium salt, 25 to 40 parts of surfactant and 20 to 30 parts of alcohol solution; The mercaptopropyl indole quaternary ammonium salt has the structural formula (I) as follows:

2. The corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields according to claim 1, It is characterized in that The mercaptopropyl indole quaternary ammonium salt comprises 35 to 50 parts of a mercaptopropyl indole compound and 50 to 65 parts of benzyl chloride; The mercaptopropyl indole compound has the structural formula (II):

3. The corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields according to claim 1, It is characterized in that The surfactant is at least one of OP-10, AEO-10, NP-10 and TX-10.

4. The corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields according to claim 1, It is characterized in that The alcohol solution is one of propanol, isopropanol and butanol.

5. The method for preparing the corrosion inhibitor for inhibiting hydrogen sulfide corrosion in oil and gas fields according to any one of claims 1 to 4, It is characterized in that The following steps are involved: S1: preparing a mercaptopropyl indole compound, stirring the mercaptopropyl indole compound and benzyl chloride at a set temperature for a set time to obtain a mercaptopropyl indole quaternary ammonium salt; S2: Stir the mercaptopropyl indole quaternary ammonium salt, the surfactant and the alcohol solution until mixed to obtain a hydrogen sulfide corrosion inhibitor.

6. The preparation method according to claim 5, It is characterized in that The steps of preparing the mercaptopropyl indole compound are as follows: Indole and 3-chloro-1-propanethiol are used as raw materials to undergo chlorination reaction in an alkaline environment to generate mercaptopropyl indole compounds.

7. The preparation method according to claim 6, It is characterized in that The mass ratio of indole to 3-chloro-1-propanethiol is (1-1.2):

1.

8. The preparation method according to claim 6, It is characterized in that The alkaline environment is an environment in which the pH value of the solution is adjusted to 10 by sodium hydroxide.

9. The preparation method according to claim 6, It is characterized in that The reaction time of the chlorination reaction is 10 hours, and the reaction temperature of the chlorination reaction is 90°C.

10. The preparation method according to claim 5, It is characterized in that In S1, the set temperature is 90-120° C.; the set time is 12 hours.

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