Titanium alloy high-temperature corrosion inhibitor and preparation method thereof

Abstract

The application belongs to the field of chemical industry, and particularly relates to a titanium alloy high-temperature corrosion inhibitor and a preparation method thereof. According to mass percentage, the titanium alloy high-temperature corrosion inhibitor comprises 20-40% of a precipitated acid salt, 0.5-1.5% of sodium hydroxide, 10-20% of polyepoxysuccinic acid sodium and 48.5-69.5% of a solvent. The titanium alloy high-temperature corrosion inhibitor is suitable for a higher temperature and a high-concentration HCl environment, has the advantages of less dosage, small corrosion rate and simplicity, and effectively alleviates the corrosion problem of a titanium alloy oil well pipe, and provides a possibility for further popularization of the titanium alloy oil well pipe.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical industry, and particularly relates to a high-temperature corrosion inhibitor for titanium alloy and a preparation method thereof. BACKGROUND

[0002] In the process of oil exploitation, the environment in the oil well is very harsh, and the oil well pipe needs to bear several hundred or even thousands of atmospheric pressure of internal or external pressure, several hundred tons of tensile load, and the influence of high temperature and corrosive medium, so the oil well pipe has a pivotal position. Titanium alloy has been favored more and more due to its advantages of low density, strong strength, wide use temperature range, and low expansion coefficient, and China has made certain progress in the development of titanium alloy oil casing, and the present product has been initially tested in the well. However, in the low-permeability oil layer, HCl is usually used to expand and communicate the pores or cracks of the rock, and to form an oil and gas seepage channel with high flow capacity in the near-wellbore zone, so how to solve the corrosion of titanium alloy oil well pipe in high-temperature HCl medium becomes a difficult problem to be solved.

[0003] However, there is less research on the corrosion prevention of titanium alloy oil well pipe in China. At present, the corrosion inhibitors for acidification mainly target carbon steel oil well pipes, such as quinoline quaternary ammonium salt, Mannich base and imidazoline, etc. It has been found through research that such corrosion inhibitors have poor corrosion prevention effect on titanium alloy in HCl, especially under high-temperature conditions. SUMMARY

[0004] In view of the poor corrosion prevention effect of the existing corrosion inhibitor on titanium alloy in HCl, the present application provides a high-temperature corrosion inhibitor for titanium alloy.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] In the first aspect, the present application provides a high-temperature corrosion inhibitor for titanium alloy, which comprises, by mass percentage: 48.5%-69% of a solvent, 0.5-1.5% of sodium hydroxide, 20%-40% of a precipitated acid salt, and 10%-20% of polyepoxysuccinic acid sodium.

[0007] Further, by mass percentage, it comprises: 49%-69% of a solvent, 0.5-1.0% of sodium hydroxide, 20%-30% of a precipitated acid salt, and 10%-20% of polyepoxysuccinic acid sodium.

[0008] Further, by mass percentage, it comprises: 48.5% of a solvent, 1.5% of sodium hydroxide, 30%-40% of a precipitated acid salt, and 10%-20% of polyepoxysuccinic acid sodium.

[0009] Further, the solvent includes, in percentage by mass: 48.5% of solvent, 1.5% of sodium hydroxide, 40% of precipitated acid salt and 10% of sodium polyepoxysuccinate.

[0010] Further, the precipitated acid salt is sodium tungstate, ammonium tungstate, sodium borate, sodium silicate, sodium tellurate or sodium stannate.

[0011] Further, the solvent is one of water and glycerol or a combination thereof.

[0012] In the second aspect, the application provides a preparation method of a high-temperature corrosion inhibitor for titanium alloy, characterized by comprising the following steps:

[0013] adding sodium hydroxide into the solvent and stirring to obtain a first agent;

[0014] adding a precipitated acid salt into the first agent and stirring until completely dissolved to obtain a second agent;

[0015] adding sodium polyepoxysuccinate into the second agent and stirring until the whole is uniformly transparent to obtain the high-temperature corrosion inhibitor for titanium alloy.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] First, the precipitated acid salt and the sodium polyepoxysuccinate have a good synergistic effect. The precipitated acid salt is easy to form a precipitate in an HCl system, adhere to the surface of a titanium alloy test piece, and the nucleophilic elements contained in the molecule can form a coordination bond with Ti atoms, thereby strengthening the adsorption of the precipitate film on the surface of the titanium alloy. The nucleophilic element O in the sodium polyepoxysuccinate is easy to be adsorbed on the surface of the titanium alloy, thereby supplementing the compactness of the protective film, effectively reducing the contact between HCl and the metal matrix, and slowing down the corrosion.

[0018] Second, the temperature in the working condition of the application is between 90-120℃, and the concentration of hydrochloric acid is between 9%-28%, which is suitable for a higher temperature and a high-concentration HCl environment, has the advantages of less amount, small corrosion rate and simplicity, and effectively alleviates the corrosion problem of titanium alloy oil well pipes, thereby providing a possibility for the further popularization of titanium alloy oil well pipes. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0020] Figure 1 Fig. 1 is a schematic diagram of the weight percentage of the high-temperature corrosion inhibitor for titanium alloy according to the application. DETAILED DESCRIPTION

[0021] The present application will be described in detail below with reference to the drawings and embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0022] The following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise defined, all technical terms used in the present application have the same meanings as those generally understood by those skilled in the art. The terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the exemplary embodiments according to the present application.

[0023] Embodiment 1

[0024] A titanium alloy high-temperature corrosion inhibitor, hereinafter referred to as the corrosion inhibitor, comprises a precipitated acid salt, a sodium polyepoxysuccinate and sodium hydroxide, wherein the precipitated acid salt is the main agent, the sodium polyepoxysuccinate is the synergist, and the sodium hydroxide is the system stabilizer. According to the mass percentage, it comprises 0.5%-1.5% sodium hydroxide, 48.5%-69% solvent, 20%-40% precipitated acid salt and 10%-20% sodium polyepoxysuccinate.

[0025] The precipitated acid salt is sodium tungstate, ammonium tungstate, sodium borate, sodium silicate, sodium tellurate or sodium stannate.

[0026] The solvent is one or a combination of water and glycerol.

[0027] In particular, according to the mass percentage, it comprises the following proportions:

[0028] 20% sodium tungstate, 0.5% sodium hydroxide, 20% sodium polyepoxysuccinate and 59.5% water;

[0029] 20% sodium borate, 1.0% sodium hydroxide, 10% sodium polyepoxysuccinate, 30% glycerol and 39% water;

[0030] 30% ammonium tungstate, 0.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 59.5% water;

[0031] 30% sodium silicate, 1.0% sodium hydroxide, 10% sodium polyepoxysuccinate and 59% water;

[0032] 30% sodium tellurate, 1.0% sodium hydroxide, 20% sodium polyepoxysuccinate and 49% water;

[0033] 30% sodium antimonate, 1.0% sodium hydroxide, 20% sodium polyepoxysuccinate and 49% water;

[0034] 30% sodium antimonate, 1.5% sodium hydroxide, 20% sodium polyepoxysuccinate and 48.5% water;

[0035] 40% sodium tellurate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 48.5% water;

[0036] 30% sodium borate, 1.5% sodium hydroxide, 20% sodium polyepoxysuccinate, 30% glycerol and 18.5% water;

[0037] 40% sodium silicate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 48.5% water;

[0038] 35% sodium tungstate, 1.5% sodium hydroxide, 15% sodium polyepoxysuccinate and 48.5% water;

[0039] 40% ammonium tungstate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 48.5% water.

[0040] Example 2

[0041] A preparation method of a high-temperature corrosion inhibitor for titanium alloy, which can specifically adopt the following steps:

[0042] Put the solvent into a beaker, add sodium hydroxide and stir until uniform to form a first agent with stable system;

[0043] Slowly add the precipitated acid salt to the first agent and stir for 10-30 min to completely dissolve the precipitated acid salt and form a second agent with certain corrosion inhibition effect;

[0044] Add sodium polyepoxysuccinate to the second agent and stir for 5-10 min until the whole is uniform and transparent, and use the synergistic effect of sodium polyepoxysuccinate and the precipitated acid salt to obtain a corrosion inhibitor capable of effectively slowing down corrosion.

[0045] Example 3

[0046] Tests are performed on the corrosion inhibitors with different proportions in Example 1, and the test steps include:

[0047] Polish the titanium alloy LH-02 sample to bright, then clean and dry it with petroleum ether and ethanol, and weigh and measure it;

[0048] Add a certain amount of prepared HCl solution to a wide-mouth bottle or an autoclave, add the corrosion inhibitor, and immerse the weighed sample;

[0049] Seal the wide-mouth bottle or the autoclave, place it in a water bath or an oven, heat it to a specific temperature, and then wait for a constant temperature for a specific time;

[0050] Turn off the water bath or the oven heating, take out the sample after cooling to room temperature, remove the corrosion product film on the surface of the sample, dry it, and then weigh and calculate the corrosion rate.

[0051] The corrosion rate measurement conditions of the corrosion inhibitor in each test example include:

[0052] Different concentrations of HCl solution, specifically including:

[0053] 9% HCl: 75% H2O + 25% concentrated HCl;

[0054] 15% HCl: 58.3% H2O + 41.7% concentrated HCl;

[0055] 20% HCl: 44.4% H2O + 55.6% concentrated HCl;

[0056] 28% HCl: 22.2% H2O + 77.8% concentrated HCl.

[0057] The test time is 4h, and the test material is titanium alloy LH-02.

[0058] Among test examples 1-6, a wide-mouth bottle is selected for preparation, 247.5g of HCl solution is added with 2.5g of corrosion inhibitor, the weight percentage of corrosion inhibitor is 1%, water bath heating is adopted, and the test temperature is 90℃.

[0059] Among test examples 7-12, a hydrothermal kettle is selected for preparation, 242.5g of HCl solution is added with 7.5g of corrosion inhibitor, the weight percentage of corrosion inhibitor is 3%, an oven is used for heating, and the test temperature is 120℃.

[0060] Test example 1

[0061] The corrosion inhibitor is composed of the following components by weight percentage: 20% sodium tungstate, 0.5% sodium hydroxide, 20% sodium polyepoxysuccinate, and 59.5% water.

[0062] Prepare 9% HCl solution 247.5g in a wide-mouth bottle, and add 2.5g of corrosion inhibitor to form an HCl system. Weighed titanium alloy LH-02 sample is immersed in the HCl system, sealed in a water bath kettle, heated to 90℃ and kept constant for 4h. Turn off the water bath heating, cool to room temperature, remove the corrosion product film on the surface of the sample, dry and weigh to calculate the corrosion rate.

[0063] The corrosion inhibitor has good solubility in HCl solution, and the static corrosion rate is 0.21g / (m 2 ·h).

[0064] Test example 2

[0065] The corrosion inhibitor is composed of the following components by weight percentage: 20% sodium tungstate, 0.5% sodium hydroxide, 20% sodium polyepoxysuccinate, and 59.5% water.

[0066] A 15% HC1 solution 247.5 g was prepared in a wide-mouthed jar and 2.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in a water bath kettle and heated to 90°C and kept constant for 4 h. The water bath heating was turned off, cooled to room temperature, the surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0067] The corrosion inhibitor had good solubility in the HC1 solution and the static corrosion rate was 0.28 g / (m 2 ·h).

[0068] Test Example 3

[0069] The corrosion inhibitor was composed of the following weight percentage components: 30% ammonium tungstate, 0.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 59.5% water.

[0070] A 15% HC1 solution 247.5 g was prepared in a wide-mouthed jar and 2.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in a water bath kettle and heated to 90°C and kept constant for 4 h. The water bath heating was turned off, cooled to room temperature, the surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0071] The corrosion inhibitor had good solubility in the HC1 solution and the static corrosion rate was 0.33 g / (m 2 ·h).

[0072] Test Example 4

[0073] The corrosion inhibitor was composed of the following weight percentage components: 30% sodium silicate, 1.0% sodium hydroxide, 10% sodium polyepoxysuccinate and 59% water.

[0074] A 20% HC1 solution 247.5 g was prepared in a wide-mouthed jar and 2.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in a water bath kettle and heated to 90°C and kept constant for 4 h. The water bath heating was turned off, cooled to room temperature, the surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0075] The corrosion inhibitor had good solubility in the HC1 solution and the static corrosion rate was 0.67 g / (m 2 ·h).

[0076] Test Example 5

[0077] The corrosion inhibitor was composed of the following weight percentage components: 30% sodium tellurate, 1.0% sodium hydroxide, 20% sodium polyepoxysuccinate and 49% water.

[0078] A 20% HC1 solution 247.5 g was prepared in a wide-mouthed jar and 2.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in a water bath and heated to 90°C and kept constant for 4 h. The water bath heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0079] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 0.51 g / (m 2 ·h).

[0080] Test Example 6

[0081] The corrosion inhibitor was composed of the following components by weight percentage: 30% sodium antimonate, 1.0% sodium hydroxide, 20% sodium polyepoxysuccinate and 49% water.

[0082] A 28% HC1 solution 247.5 g was prepared in a wide-mouthed jar and 2.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in a water bath and heated to 90°C and kept constant for 4 h. The water bath heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0083] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 0.97 g / (m 2 ·h).

[0084] Test Example 7

[0085] The corrosion inhibitor was composed of the following components by weight percentage: 30% sodium antimonate, 1.5% sodium hydroxide, 20% sodium polyepoxysuccinate and 48.5% water.

[0086] A 9% HC1 solution 242.5 g was prepared in an autoclave and 7.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system, sealed in an oven and heated to 120°C and kept constant for 4 h. The oven heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0087] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 1.45 g / (m 2 ·h).

[0088] Test Example 8

[0089] The corrosion inhibitor was composed of the following components by weight percentage: 40% sodium tellurate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 48.5% water.

[0090] A 242.5 g 9% HC1 solution was prepared in an autoclave and 7.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system and sealed in an oven and heated to 120°C and held for 4 h. The oven heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0091] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 0.86 g / (m 2 ·h).

[0092] Test Example 9

[0093] The corrosion inhibitor was composed of the following weight percent components: 30% sodium borate, 1.5% sodium hydroxide, 20% sodium polyepoxysuccinate, 30% glycerol and 18.5% water.

[0094] A 242.5 g 15% HC1 solution was prepared in an autoclave and 7.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system and sealed in an oven and heated to 120°C and held for 4 h. The oven heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0095] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 0.69 g / (m 2 ·h).

[0096] Test Example 10

[0097] The corrosion inhibitor was composed of the following weight percent components: 40% sodium silicate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate and 48.5% water.

[0098] A 242.5 g 20% HC1 solution was prepared in an autoclave and 7.5 g of the corrosion inhibitor was added to form the HC1 system. The weighed titanium alloy LH-02 sample was immersed in the HC1 system and sealed in an oven and heated to 120°C and held for 4 h. The oven heating was turned off and the sample was allowed to cool to room temperature. The surface corrosion product film was removed, dried and weighed to calculate the corrosion rate.

[0099] The corrosion inhibitor was well soluble in the HC1 solution and the static corrosion rate was 1.27 g / (m 2 ·h).

[0100] Test Example 11

[0101] The corrosion inhibitor was composed of the following weight percent components: 35% sodium tungstate, 1.5% sodium hydroxide, 15% sodium polyepoxysuccinate and 48.5% water.

[0102] A 20% HCl solution of 242.5 g was prepared in an autoclave, and 7.5 g of the corrosion inhibitor was added to form an HCl system. The titanium alloy LH-02 sample was immersed in the HCl system, and was sealed in an oven and heated to 120°C and kept at this temperature for 4 h. The oven heating was turned off, and the sample was cooled to room temperature. The corrosion product film on the surface of the sample was removed, dried, weighed, and the corrosion rate was calculated.

[0103] The corrosion inhibitor has good solubility in the HCl solution, and the static corrosion rate is 1.39 g / (m 2 ·h).

[0104] Test Example 12

[0105] The corrosion inhibitor is composed of the following components by weight percentage: 40% ammonium tungstate, 1.5% sodium hydroxide, 10% sodium polyepoxysuccinate, and 48.5% water.

[0106] A 20% HCl solution of 242.5 g was prepared in an autoclave, and 7.5 g of the corrosion inhibitor was added to form an HCl system. The titanium alloy LH-02 sample was immersed in the HCl system, and was sealed in an oven and heated to 120°C and kept at this temperature for 4 h. The oven heating was turned off, and the sample was cooled to room temperature. The corrosion product film on the surface of the sample was removed, dried, weighed, and the corrosion rate was calculated.

[0107] The corrosion inhibitor has good solubility in the HCl solution, and the static corrosion rate is 1.15 g / (m 2 ·h).

[0108] The test example values are as shown in the following table:

[0109]

[0110] It is to be understood by those skilled in the art that the present application can be carried out by other embodiments not mentioned above without departing from the spirit or essential characteristics of the application. Accordingly, the above disclosed embodiments are merely exemplary and are not the only way in which the present application can be practiced. All modifications and alterations which come within the scope of or which replace equivalents of the present application are to be embraced by the below claims.

[0111] Finally, it should be noted that the above examples are merely used to illustrate the technical solutions of the present application and not to limit the same. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be embraced by the claims of the present application.

Claims

1. A method for preparing a high temperature corrosion inhibitor for titanium alloys, characterized in that, The method comprises the following steps: adding sodium hydroxide into the solvent and stirring to obtain a first agent; adding a precipitated acid salt into the first agent and stirring until completely dissolved to obtain a second agent; adding sodium polyepoxysuccinate into the second agent and stirring until the whole is uniformly transparent to obtain a titanium alloy high-temperature corrosion inhibitor; The titanium alloy high-temperature corrosion inhibitor comprises, in percentage by mass, 48.5%-69% of a solvent, 0.5-1.5% of sodium hydroxide, 20%-40% of a precipitated acid salt and 10%-20% of sodium polyepoxysuccinate; the precipitated acid salt is selected from sodium tungstate, ammonium tungstate, sodium silicate or sodium stannate; the solvent is one of water and glycerol or a combination thereof; wherein the titanium alloy high-temperature corrosion inhibitor is applicable to a working condition of a high temperature of 90-120 DEG C and an HCl concentration of 9%-28%; the precipitated acid salt and the sodium polyepoxysuccinate synergistically form a protective film on the surface of the titanium alloy to reduce the corrosion rate.

2. The preparation method according to claim 1, characterized in that, The titanium alloy high-temperature corrosion inhibitor comprises, in percentage by mass, 49%-69% of a solvent, 0.5-1.0% of sodium hydroxide, 20%-30% of a precipitated acid salt and 10%-20% of sodium polyepoxysuccinate.

3. The preparation method according to claim 1, characterized in that, The titanium alloy high-temperature corrosion inhibitor comprises, in percentage by mass, 48.5% of a solvent, 1.5% of sodium hydroxide, 30%-40% of a precipitated acid salt and 10%-20% of sodium polyepoxysuccinate.

4. The preparation method according to claim 1, characterized in that, The titanium alloy high-temperature corrosion inhibitor comprises, in percentage by mass, 48.5% of a solvent, 1.5% of sodium hydroxide, 40% of a precipitated acid salt and 10% of sodium polyepoxysuccinate.

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