WO2007112620A1

WO2007112620A1 - An inhibitor of inhibiting metal corrosion and the preparing method of it

Info

Publication number: WO2007112620A1
Application number: PCT/CN2006/002160
Authority: WO
Inventors: Tan Gu; Yongbi HU; Yongfan TANG; Zhide LIU; Liming Huang; Zhongxi YANG; Ying Huang; Jian Wang; Honggang CHANG; Huali YU; Guohao LI; Jun Cao
Original assignee: Petrochina Company Limited
Priority date: 2006-04-04
Filing date: 2006-08-24
Publication date: 2007-10-11
Also published as: CN100526508C; CN101050537A

Abstract

The present invention defines an inhibitor of inhibiting metal corrosion which is used in the metal pipes of heavy acidic gas field and anti-corrosion of the devises, and it also defines a preparing method of it. The inhibitor contains 25~50% of the derivatives of imidazole which have sulfur, 5~10% of auxiliaries, 5~10% of surfactant and 30~55% of solvent oil. The inhibitor has the advantages that the films formed by it have high strength and they have long working time more than 240 hours. It has good protection effects to the metal pipes in the petrol and gas well. And the rate of inhibiting corrosion is not less than 90%.

Description

Corrosion inhibitor for inhibiting metal corrosion and preparation method thereof

Technical field

The invention relates to a corrosion inhibitor for corrosion protection of metal pipelines and equipment in the production of oil and gas fields, especially high acid gas fields, and a preparation method thereof.

Background technique

The inventor conducted a large amount of literature retrieval work on domestic and foreign background technology. For example, a typical domestic patent CN1277240, which is a product consisting of a combination of an imidazoline sulfur derivative, an alkyl phosphate, an alkyne alcohol, a nonionic surfactant and a solvent. It is also used for the corrosion protection of high carbon dioxide and high salinity oil wells. However, unlike the structural composition of the present invention, the application field does not target a system containing high hydrogen sulfide-high carbon dioxide-high salinity. The duration has not been reported in detail. Therefore, the present invention differs from other domestic patent reports in the selection of the use environment and the formulation of the corrosion inhibitor.

In the case of foreign literature and patents, the inventors also conducted patent searches. There are patents for corrosion inhibitors applied in high acid gas fields by SHELL OIL COMPANY, etc., but the basic components are mostly quaternary ammonium salts containing heterocyclic rings or thioethers containing alkyl groups and aromatic groups. The H ₂ S content in the use environment is up to 700 mg/L, and no partial pressure conditions are mentioned in the patent, and no film duration of the corrosion inhibitor is given. For example, the US patent USP H1, 147, the corrosion inhibitor of this patent is a metal corrosion inhibitor suitable for the production line of a high-acid oil and gas field containing hydrogen sulfide, and its main component is a thioether compound of the formula R-S_S-R1. It is used in combination with a film-forming corrosion inhibitor to control the corrosion of free sulfur. The corrosion inhibitor was tested at 82. 2 ° C, sodium chloride content 1000 mg / L, hydrogen sulfide gas content 5%, carbon dioxide gas content 30%, pressure 1000 psi with high pressure runner for 24 hours, plus When the amount is from 1000 to 5000 mg/L, the corrosion rate can be controlled from 0.449 to 3.675 mm/y for the material of the Rod 1018 carbon steel. It has different structure from the agent of the present invention, and requires multiple components to be compounded, and the product composition is complicated and high in cost, and it has not been reported in detail on the film duration.

Summary of the invention

The object of the present invention is to invent a corrosion inhibitor capable of controlling metal corrosion in a high hydrogen sulfide-containing high carbon dioxide-high salinity corrosive environment, which can have a NaCl content of up to 5% and an H ₂ S content of up to 1000 mg. /L, C0 ₂ content of up to 800mg / L, and containing Mg ²⁺ , Ca ²⁺ , C0 ₃ ² \ HCCV , S0 ₄ ² - plasma corrosive medium, used at a temperature of 30 ~ 80 ° C, It can also exert good corrosion protection in H ₂ S partial pressure 1.5, MPa, C0 ₂ partial pressure 1.5MPa, total pressure lOMPa, temperature 30~80 °C, and can be used for most downhole pipeline metal materials and Anti-corrosion of metal materials for surface oil and gas gathering pipelines.

The invention relates to a corrosion inhibitor for inhibiting metal corrosion in a high acid gas field, the basic composition of which is a sulfur-containing imidazoline derivative, comprising an imidazoline ring structure, an alkyl branch of C ₇ -C ₁₇ , an amide group and a thiol group. .

The basic formula of the corrosion inhibitor of the invention:

Type I is: SOsH- (CH ₂ ) ) p— NH— CO— R ₂

Wherein: is a branched or unbranched, saturated or unsaturated C plant C ₁₇ decyl or nonenyl;

R ₂ is - C0 ₂ H, - S0 ₃ H, -PO3H2, C0 ₂ R ₅ , - C0NH ₂ or -C0NHR ₅ wherein R ₅ is an alkyl group having 1 to 8 carbon atoms, an aryl group, an alkylaryl group Or ring thiol; rFp=l-5;

Type II is:

, Rs

Re—(CH ₂ ) r— SH— (CH ₂ ) q— R ₄

CH ₂ (CH ₂ ) _n

Wherein: is a saturated or unsaturated C ₅ -C ₂₃ alkyl or alkenyl group, a hydroxyl group, a decyl group or a phosphate group with or without a branch; is a polyene polyamine, C ₂ - C _1Q Alcohol or triol;

Re is - C0 ₂ H, _S0 ₃ H, -PO3H2, -CO2R7, - C0NH2 or - C0NHR ₇ , where R ₇ Is a branched or linear alkyl group having 1-8 carbon atoms, an aryl group, a decylaryl group or a cycloalkyl group; r=q=2-10; n=1-5.

The auxiliary agent D in the corrosion inhibitor formulation is d-C ₃ enol or polyenol, which is ethanol, isopropanol or ethylene glycol; surfactant E can be ethoxylated nonylphenol, ethoxylated amine , p-toluenesulfonic acid or dodecylbenzenesulfonic acid; solvent oil F is diesel or kerosene.

The specific process is as follows:

Explain the production process of corrosion inhibitor of general formula II

The starting material organic carboxylic acid A, represented by R ₈ -C00H, usually selects linear or branched saturated or unsaturated fatty acids ranging from C _{6 to} C ₃₀ , or oxidized, sulfurized and phosphorylated fatty acids, ie carbon The chain contains 0, S, P, and the fatty acid with a carbon chain length of 7-24 has the best effect;

Starting material B is an alkylamine which can be represented by the following formula:

H ₂ N—CH ₂ — (CH ₂ ) p— NH—(CH ₂ ) q—丽 2

Wherein p = l- 5, q = 2- 10; the most common choice is p = l- 2, q 3 alkylamine di-2; C starting material of the formula R ₉ - SH sulfur-containing organic compound may be It is an alkyl group, an alkenyl group and a carboxylic acid group of C ₂ - C ₅ .

The course of the reaction is as follows: The starting material A of the formula Rs-COOH is of the formula N-CH ₂

― (CH ₂ ) p—NH—(CH ₂ ) q—N The raw material B is mixed in a molar ratio of 2: 1. 1~2: 2. 5, at 6CTC, the specific step is to first add A to the reactor. Then, heat up to 60 °C, start nitrogen protection, then add B quickly, and continue to raise the temperature to 170 °C ~ 190. C, In this temperature range of reaction 1. 5~2. 5 hours, the general formula is R ₃ - C0 - Li - CH ₂ - (CH ₂ ) p - NH - . (CH ₂ ) q - NH- CO - R4 intermediate 1, R ₃ and R ₄ may be the same, It can also be different; then continue to raise the temperature to 220 ° C ~ 240 ° C, constant temperature reaction at this temperature for 3 to 5 hours, to obtain the intermediate 2 of the following formula, cooling to 12 CTC for use;

CH ₂ (CH ₂ ) n Then, a raw material C of the formula -SH is added dropwise to the above reaction system at a uniform rate, and the second step reaction is continued. The molar ratio of the intermediate 2 to the raw material C is controlled at 1:1. 1~1: 1. 5, Maintaining nitrogen-passing conditions, controlling the temperature range of 120 ° (: ~ 130 ° C, constant temperature reaction for 4 to 6 hours, to obtain the desired product II of the reaction, which can be represented by the following formula.

Rs

The reaction product II is compounded with a solvent, a surfactant and an auxiliary agent to obtain a target corrosion inhibitor < the content percentage range of each component in the formulation of Table 1

Component name content range, %

Reaction product II 25~50

D 5~10

E 5~10

F. 55~30 detailed description

Example 1

Preparation of sulfamide-containing imidazoline

The reaction is carried out in a four-necked flask or a chemical reactor (e.g., a Lab Max reactor) using a mixture of an industrial oleic acid (containing 40% oleic acid) and tetraethylenepentamine in a molar ratio of 2:1. The flask was equipped with a stirrer, an inlet funnel (same as the nitrogen-protected inlet), a thermometer, and a branch pipe connected to the water separator and condenser. The industrial oleic acid was heated to 60 ° C under nitrogen-passing conditions, and then tetraethylenepentamine was rapidly added dropwise through a separatory funnel, and the mixture was stirred constantly, and the temperature was raised to 170 °C. At this point, the water is separated by about 1 mole. In this case the infrared spectrum showed absorptions at 1630cm- ¹ amide at 1550cm- ^1, N- H at ^a free state has an absorption peak at SSlScnf. Then, the temperature was further raised to 220 ° C and the reaction was carried out for 3 hours. An amide imidazoline is formed. The infrared spectrum showed a characteristic absorption peak of imidazoline at 1610cnT. The mass of the product was calculated from the yield, and thioglycolic acid was added to the product in a molar ratio of 1:1. The reaction was continued at 120 ° C for 4 hours to form a sulfur-containing imidazoline derivative.

The final reaction product is compounded with an adjuvant to form a corrosion inhibitor product. Formulated as: 40% final product, 50% solvent oil, 5% sodium dodecylbenzene sulfonate, 5% isopropanol.

Evaluation results of the corrosion inhibitor product of Example 1 :

Static atmospheric pressure evaluation

Evaluation conditions: NaCl _: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, Na ₂ S0 ₄ 4700 mg/L, H ₂ S 100 mg/L, C0 ₂ 400 mg/L, test temperature 40 ° C, atmospheric pressure, test time 72 hr, The corrosion inhibitor concentration is 100mg/L, 'the test material is 20# tube steel and L245. The test results are shown in Table 1. Table 1 Static and normal pressure evaluation of corrosion inhibitor of Example 1

2. Dynamic high pressure evaluation

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, Na ₂ S0 ₄ 4700 mg/L, S content: 1000 mg/L, and C0 ₂ content: 400 mg/L. Test temperature 60 test time 24 hr, test pressure 10 MPa, speed 250 rpni, corrosion inhibitor concentration 200 mg / L, test material is VM80SS, test results are shown in Table 2. Table 2 Dynamic high temperature and high pressure evaluation

3. Corrosion inhibitor film durability evaluation

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, N3⁄4S0 ₄ 4700 mg/L, H ₂ S 1000 mg/L, C0 ₂ 400 mg/L, test temperature 40 ° C, atmospheric pressure, 1% of Example 1 Corrosion inhibitor pre-film, test material 20# steel. Its membrane lasts for 210-240 hours.

Example 2

First, the industrial linolenic acid and diethylenetriamine are reacted in a reactor at a molar ratio of 2:1.2, and the linolenic acid is heated to 50 ° C under nitrogen-passing conditions, and then rapidly dripped through a separatory funnel. Add, and the mixture is stirred continuously, and the temperature is raised to 16 CTC. At this time, about 1 mole of water is separated, and then the temperature is further raised to 225 ° C, and the reaction is carried out for 3 hours to form a amide. Oxazoline. The infrared spectrum showed a characteristic absorption peak of imidazoline at 1610 cm-l, the mass of the product was calculated according to the yield, and mercaptopropionic acid was added to the product at a molar ratio of 1: 1., and the reaction was continued at 13 CTC. After 4 hours, a sulfur-containing imidazoline derivative was formed.

The final reaction product is compounded with an adjuvant to form a corrosion inhibitor product. Formulated as: 50% final product, 40% mineral spirits, 5% ethoxylated nonylphenol, 5% ethylene glycol.

Evaluation results of the corrosion inhibitor product of Example 2:

1, static atmospheric pressure evaluation

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, N3⁄4S0 ₄ 4700 mg/L, 3⁄4S 1000 mg/L, C0 ₂ 400 mg/L, test temperature 40° (:, atmospheric pressure, test time 72 hr, corrosion inhibitor The concentration is 100mg/L, the test material is 20# tube steel and L245NB, the test results are shown in Table 3 o

Table 3 Static and normal pressure evaluation of corrosion inhibitor of Example 2

2. Dynamic high pressure evaluation

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, N3⁄4S0 ₄ 4700 mg/L, H ₂ S amount: 1000 mg/L, and C0 ₂ content: 400 mg/L. The test temperature is 60 ° C, the test time is 24 hr, the test pressure is 10 MPa, the rotation speed is 250 rpm, the corrosion inhibitor concentration is 200 mg/L, the test material is VM80SS, and the test results are shown in Table 4.

Table 4 Dynamic high temperature and high pressure evaluation

Corrosion inhibitor code Corrosion rate, mm/a Corrosion inhibition rate, % Test piece surface condition

Blank 0. 3155

Example 2 0. 0261 91. 7 After the test piece is processed, the film is bright and the film formation is obvious. • 3, corrosion inhibitor film durability evaluation

繊 ^:

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, Na ₂ S0 ₄ 4700 mg/L, H ₂ S 100 mg/L. C0 ₂ 400 mg/L, test temperature 40° (:, atmospheric pressure, 1% implementation The corrosion inhibitor pre-film of Example 1 was tested on material 20# steel. The film lasting time was 220-240 hours. Example 3 First, the molar ratio of sulfonated castor oil to tetraethylene pentamine in 2: 1. 1 The reaction was carried out in the reactor, and the linolenic acid was heated to 70 ° C under nitrogen-passing conditions, and then rapidly added dropwise through a separatory funnel, and the mixture was stirred constantly, and the temperature was raised to 175 ° C. 1 mole, then continue to raise the temperature to 225 ° C, and react for 3 hours to form a sulfonated imidazoline. Infrared spectroscopy shows a characteristic absorption peak of imidazoline at 1610 cm-1, and the mass of the product is calculated according to the yield, and is 1: 1. The molar ratio of 2 is added to the product, and the reaction is continued for 4 hours at 125 ° C to form a sulfur-containing imidazoline derivative. The final reaction product and the auxiliary agent are compounded into a corrosion inhibitor product. The formulation is: 45% final product, 45% mineral spirits, 5% ethoxylated amine, 5% ethylene glycol. Agent product evaluation results:

1. Evaluation conditions of static atmospheric pressure: NaCl: 32000mg/L, NaHC0 ₃ : 2300mg/L, Na ₂ S0 ₄ 4700mg/L, H ₂ S 1000mg/L, C0 ₂ 400mg/L, test temperature 40°C, often Pressure, test time 72 hr, corrosion inhibitor concentration 100 mg / L, test material is 20 # tube steel and L245, the test results are shown in Table 5.

Table 5 Example 3 Static and normal pressure evaluation of corrosion inhibitor

Corrosion inhibition test surface test material solubility

Mm/a % condition blank 20# pipeline steel 0.4475 uniform corrosion Example 3 20# pipeline steel oil-soluble water dispersion 0.0138 96.9 uniform bright blank L245 0.1123 uniform corrosion example 3 L245 oil-soluble water dispersion 0.0115 89.7 uniform bright

2. Dynamic high pressure evaluation

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, Na ₂ S0 ₄ 4700 mg/L, 3⁄4S content: 1000 mg/L, and C0 ₂ content: 400 mg/L. The test temperature was 60 ° C, the test time was 24 hr, the test pressure was 10 MPa, the rotation speed was 250 rpm, and the corrosion inhibitor concentration of Example 3 was 200 mg/L. The test material was VM80SS, and the test results are shown in Table 6.

Table 6 Example 3 Dynamic High Temperature and High Pressure Evaluation

3. Persistence evaluation of corrosion inhibitor film

Evaluation conditions: NaCl: 32000 mg/L, NaHC0 ₃ : 2300 mg/L, N3⁄4S0 ₄ 4700 mg/L, H ₂ S 100 mg/L, C0 ₂ 400 mg/L, test temperature 40 ° C, atmospheric pressure, 1% of Example 1 Corrosion inhibitor pre-film, test material 20# steel. Its membrane lasting time is greater than 220 hours.

Industrial applicability

The corrosion inhibitor of the invention can have a NaCl content of up to 5%, a H ₂ S content of up to 1000 mg/L, a C0 ₂ content of up to 800 mg/L, and contains Mg ²⁺ , Ca ²⁺ , C0 ₃ ² \ HC0 ₃ \ S0 ₄ ² —The corrosive medium of plasma is well used at a temperature of 30~80 °C, and can be divided into 1.5 MPa at H ₂ S, 1.5 MPa at a pressure of C0 ₂ , a total pressure of 10 MPa, and a temperature of 30 to 80 ° C. In the case of the case, it still plays a good role in corrosion protection. It can be used for the corrosion protection of metal materials of most underground pipelines and ground oil and gas gathering pipelines, such as A3 carbon steel, 20# pipeline steel, L245 pipe steel, L360 pipe steel, etc. Oil and gas transmission pipeline metal surface has Very good anti-corrosion effect, corrosion inhibition rate of 90%. In the VM80SS, VM110SS, NT80SS and other oil and gas wells, the oil casing metal surface also has a good protective effect, and the corrosion inhibition rate is 90%. The outstanding feature of the corrosion inhibitor is that the film forming strength is high and the film lasts for more than 240 hours, which is much higher than the conventional corrosion inhibitor. The metal pipeline can be protected by batch processing (BATCH) or intermittent filling in the field.

Claims

Claim

A corrosion inhibitor for inhibiting metal corrosion, characterized in that it comprises 25 to 50% of a sulfur-containing imidazoline derivative, 5 to 10% of an auxiliary agent, 5 to 10% of a surfactant, and 30 to 55 by weight. % solvent oil composition;

The basic formula of the sulfur-containing imidazoline derivative is:

Ri

SO3H- (CH ₂ ) (CH ₂ ) p— ΝΉ—CO— R ₂

Wherein: is a branched or unbranched, saturated or unsaturated C ₇ -C ₁₇ alkyl or alkenyl group; n two p = l - 5; R2 is - C0 ₂ H, - S0 ₃ H, - P0 _{3 3⁄4} , C0 ₂ R ₅ , -C0N3⁄4 or -CONHRs, wherein is a fluorenyl, aryl, alkylaryl or cycloalkane having from 1 to 8 carbon atoms or its basic formula is:

R ₃

Wherein: R ₃ is a saturated or unsaturated C ₅ -C23 alkyl or decenyl, hydroxy, decyl or phosphate group with or without branching; R ₄ is a polyene polyamine, C ₂ -C _1Q diol or triol; R ₆ is - C0 ₂ H, - S0 ₃ H, - P0 ₃ H ₂ , C0 ₂ R ₇ > - C0NH ₂ or - C0NHR ₇ , wherein R ₇ is 1-8 carbons a branched or straight-chain alkyl group, an aryl group, an alkylaryl group or a cycloalkyl group; rq-2—10; n=1-2;

Aid is Cr ~ C ₃ alcohol or poly-alcohol;

The surfactant is ethoxylated nonylphenol, ethoxylated amine, p-toluenesulfonic acid or dodecylbenzenesulfonic acid; the solvent oil is diesel or kerosene.

2. A corrosion inhibitor for inhibiting metal corrosion according to claim 1, wherein the auxiliary agent is ethanol, isopropanol or ethylene glycol.

3. A method for preparing a corrosion inhibitor for inhibiting metal corrosion, characterized in that: the sulfur-containing imidazoline derivative is prepared by mixing the organic carboxylic acid A with the alkylamine B in a molar ratio of 2: 1. 1 to 2: 2. 5, fully mixed at 60 ° C, first add A in the reactor, then warmed to 60 ° C, began to protect with nitrogen, then quickly drop B, and continue to raise the temperature to 170 ° C ~ 190 ° C, here In the temperature range of 1. 5~2. 5 hours, the intermediate 1 carboxylic acid amine is formed; 'then continue to raise the temperature to 220 ° C ~ 240 ° C, the temperature is constant at this temperature for 3 to 5 hours to form the intermediate 2 imidazole The porphyrin; then the temperature of the reaction system is lowered to 120 ° C ~ 130 ° C, and the sulfur-containing organic acid C is added dropwise to the intermediate 2 at a uniform rate, the molar ratio of the intermediate 2 to C is controlled at 1:1 1~1: 1. 5, maintain nitrogen-passing conditions, and continue to react at a constant temperature of 120 ° C ~ 130 ° C for 4 to 6 hours to obtain a final product containing sulfamide imidazoline;

The organic carboxylic acid A is represented by the formula -C00H and is a linear or branched saturated or unsaturated fatty acid; Raw material alkylamine B is of general formula

H ₂ N—CH ₂ — (CH ₂ ) p— H — (CH ₂ ) q—N3⁄4 means that

Where p=l-5, q=2-10;

The sulfur-containing organic acid C has the formula R ₉ —SH, and R ₉ is a C ₂ —C ₅ alkyl group, an alkenyl group and a carboxylic acid group.

The method for producing a corrosion inhibitor for inhibiting metal corrosion according to claim 2, wherein the organic carboxylic acid A is a fatty acid having 0, S, and P in the carbon chain.

The method for preparing a corrosion inhibitor for inhibiting metal corrosion according to claim 2, wherein the organic carboxylic acid A is a fatty acid having a carbon chain length of from 7 to 24.

6. The method for preparing a corrosion inhibitor for inhibiting metal corrosion according to claim 2, wherein: the starting material mercaptoamine B is of the formula:

H ₂ N—CH ₂ — (CH ₂ ) p—NH—(CH ₂ ) q—NH ₂ represents,

Where p = l - 2, q = 2 - 3.