WO2019139080A1 - Corrosion inhibitor composition, mixed transport fluid, corrosion inhibitor composition charging method, well, and pipeline - Google Patents

Abstract

This corrosion inhibitor composition contains: a long-chain organic compound that has a polar group; and hydrophobic silica. A corrosion inhibitor composition charging method in which a mixed fluid that includes water and at least one type of hydrocarbon fluid selected from the group that consists of liquid-phase hydrocarbon fluids and gas-phase hydrocarbon fluids is charged with a corrosion inhibitor composition that comprises: a first corrosion inhibitor composition that includes a long-chain organic compound that has a polar group; and a second corrosion inhibitor composition that includes hydrophobic silica.

Description

Corrosion inhibitor composition, transport mixed fluid, method of injecting corrosion inhibitor composition, well and pipeline

The present invention relates to corrosion inhibitor compositions, transport mixed fluids, methods of injecting corrosion inhibitor compositions, wells and pipelines.
Priority is claimed on Japanese Patent Application No. 2018-002918, filed January 11, 2018, the content of which is incorporated herein by reference.

In oil wells that produce oil and production wells such as gas fields that produce natural gas, the material of the oil collection tube (tubing) installed to guide oil and natural gas from the oil layer and gas layer to the ground inside the casing is Mainly carbon steel and stainless steel. In addition, carbon steel, stainless steel, etc. are adopted as the material of the transport pipe of the pipeline constructed to transport oil and natural gas from the production well to the treatment facility and the delivery terminal.
Crude oil and natural gas as mined from underground contain corrosive gases such as carbon dioxide and hydrogen sulfide as well as water. Therefore, it is necessary to consider the corrosion of the inner surface by the wet corrosive gas in the oil production pipe of the production well and the transportation pipe of the pipeline.

As a method of preventing corrosion of the metal of the outer surface of the drill pipe used for mining development of petroleum and natural gas, for example, Patent Document 1 discloses an organic inhibitor such as long chain fatty acids in suppressing local corrosion of metals. Methods are disclosed for adding (inhibitors) and hydrocarbon oils such as aromatic hydrocarbons.

Further, Patent Document 2 discloses a method of suppressing the corrosion rate of water by adjusting the concentration of silica in water circulating through a pipe made of an iron-based metal in the method of suppressing the corrosion of an iron-based metal by water. It is done.

JP 2000-219980 A JP 2004-132636 A

Patent Document 1 shows a method of using an amine-based organic compound or lauric acid as an inhibitor and adding it to drilling mud together with a hydrocarbon oil such as iso-octane or xylene, but it is not always necessary to develop petroleum and natural gas mining It was not satisfactory to prevent the corrosion of the metal in the inner surface of the cut pipe used.
In the method used in Patent Document 2, although the corrosion prevention effect to water of hydrophilic silica such as sodium silicate and potassium silicate has been confirmed, the production wells of oil fields, gas fields, etc. where crude oil components are mixed The effect of preventing corrosion against wet corrosive gases including carbon dioxide and hydrogen sulfide that are exposed when used in equipment has not been confirmed.

The present invention has been made in view of the above circumstances, and is a corrosion inhibitor which can sufficiently prevent the corrosion by the wet corrosive gas containing carbon dioxide, hydrogen sulfide, etc. on the inner surface of the oil pipe of production well and the transportation pipe of pipeline. Composition, transport mixed fluid, method of injecting corrosion inhibitor composition, well and well and pipeline intended to be provided.

The present invention is characterized by having any of the following aspects.
[1] A corrosion inhibitor composition comprising an organic long chain compound having a polar group and a hydrophobic silica.
[2] The corrosion inhibitor composition according to [1], further comprising an organic solvent.
[3] containing at least one hydrocarbon fluid selected from the group consisting of liquid phase hydrocarbon fluid and gas phase hydrocarbon fluid, water, organic long chain compound having polar group and hydrophobic silica And a corrosion inhibitor composition.
[4] The transport mixed fluid according to [3] or [4], wherein the organic long chain compound having a polar group has one or more selected from nitrogen, oxygen, and sulfur.
[5] The transport mixed fluid according to [3] or [4], wherein the corrosion inhibitor composition further contains an organic solvent.
[6] The transport mixed fluid according to [5], wherein the organic solvent is a liquid phase under temperature and pressure that are transport conditions of the transport mixed fluid.
[7] The transport mixed fluid according to [5] or [6], wherein the organic solvent is an aromatic compound.
[8] A method for introducing a corrosion inhibitor composition, which comprises mixing with at least one hydrocarbon fluid selected from the group consisting of liquid hydrocarbon fluid and gaseous hydrocarbon fluid, and water. A first corrosion inhibitor composition comprising a corrosion inhibitor composition charging step of charging a corrosion inhibitor composition into a fluid, the corrosion inhibitor composition comprising an organic long chain compound having a polar group; And a second corrosion inhibitor composition containing hydrophobic silica.
[9] The method for charging the corrosion inhibitor composition according to [8], wherein the second corrosion inhibitor composition further contains an organic solvent.
[10] The corrosion inhibitor composition charging step includes charging the first corrosion inhibitor composition and the second corrosion inhibitor composition separately into the mixed fluid, [8] Or the injection | pouring method of the corrosion inhibitor composition as described in [9].
[11] A well comprising a tubing having an anticorrosive coating formed on the inner surface by the corrosion inhibitor composition according to [1] or [2].
The well in the present invention is not limited to production wells such as oil fields and gas fields, but is a well for injecting gas and water into the ground, and for observing the state of the ground with the production of crude oil and natural gas. Such as observation wells, etc., including equipment having a pipe that may cause corrosion of the inner surface by corrosive gas.
[12] A pipeline including a transport pipe having an anticorrosive coating formed on the inner surface by the corrosion inhibitor composition according to [1] or [2].
The pipeline in the present invention is a facility for transporting fossil fuel such as extracted oil and natural gas, and does not refer to a simple assembly of pipes.

According to the corrosion inhibitor composition of the present invention and the transport mixed fluid containing the corrosion inhibitor composition of the present invention, the inner surface of the oil production pipe of the production well, the transport pipe of the pipeline, etc. Corrosion of members exposed to the phase can be sufficiently prevented.
In addition, according to the method for charging the corrosion inhibitor composition of the present invention, hydrophobic silica is efficiently dispersed, and the inner surface of the oil well pipe of the production well, the transport pipe of the pipeline, etc. contains the wet corrosive gas. Corrosion of members exposed to the liquid phase can be sufficiently prevented.
In addition, in the well and pipeline of the present invention, the inner surfaces of the oil production pipe and the transport pipe are not easily corroded. Thereby, the service life of the oil collection pipe and the transport pipe can be extended, and the operation cost of the facility can be suppressed.

It is sectional drawing which shows typically an example of the oil production pipe | tube contained in the well of this invention. It is the elements on larger scale of FIG. It is a schematic diagram which shows each installation of the oil field aiming at oil production. It is the schematic which shows an example of the production well of FIG. It is the schematic which shows the other example of the production well of FIG. It is the schematic which shows an example of the pipeline system of FIG. It is a schematic diagram which shows the apparatus for measuring the corrosion rate used by test 1. FIG. It is a graph which shows the result (proof corrosion rate) of examination 1.

Hereinafter, although an example of an embodiment of the present invention is described in detail, the present invention is not interpreted as limiting to these embodiments.

"Corrosion inhibitor composition"
The corrosion inhibitor composition of the present embodiment contains an organic long chain compound having a polar group capable of providing an electron to a metal, and a hydrophobic silica. The corrosion inhibitor composition of the present embodiment preferably further contains an organic solvent.
Each component will be described below.

<Organic long chain compound>
Organic long-chain compounds have polar groups capable of donating electrons to metals, and long-chain hydrophobic groups, and are called inhibitors.
The polar group capable of donating electrons to the metal includes one containing one or more elements selected from the group consisting of nitrogen (N), oxygen (O), and sulfur (S). Specific examples thereof include a carboxy group and a salt thereof as a polar group, a hydroxy group, a group having a basic nitrogen (for example, an amino group etc.) and a salt thereof, and a sulfonic acid group and a salt thereof. Examples of the salt include alkali metal salts and alkaline earth metal salts.
When the inner surface of the oil collection pipe or pipeline is a bare metal, it is preferable to select a polar group containing nitrogen, and when a passive film is formed on the inner surface of the pipeline, a carboxy group is used as a polar group It is preferable to select.
The number of polar groups may be one or two or more in one molecule. When the organic long chain compound has two or more polar groups, the types of polar groups may be the same or different.
Examples of the long chain hydrophobic group include an alkyl group having 8 to 20 carbon atoms and an alkenyl group having 8 to 20 carbon atoms.

The organic long-chain compound is adsorbed on the metal surface when the polar group supplies electrons to the metal to form a layer (film). Such organic long chain compounds are also referred to as "adsorption type inhibitors" or "filming amines".

Examples of organic long-chain compounds include sodium N-dodecanoyl sarcosinate, dodecylamine, stearic acid, lauric acid, oleic imidazoline and the like.
Alternatively, commercially available organic long-chain compounds may be used, such as water-soluble inhibitors (trade name: “EC1304A”) manufactured by Nalco Champion, oil-soluble / water-dispersible inhibitors (trade name: “EC1103A”), etc. It can be mentioned.
These organic long-chain compounds may be used alone or in combination of two or more.

In facilities of oil and gas fields where water and crude oil components are mixed, amine long-chain organic compound with a smaller specific gravity than water does not disperse uniformly in the water phase, but oil / water separates. There is a possibility of reducing the anticorrosion effect of the bottom of the water phase in a pipeline or the like.
Therefore, it is more preferable to use hydrophobic nanoparticles, which is a hydrophobic compound having a specific gravity larger than that of water.
In addition, organic long-chain compounds and the like have high dispersibility in water, and can be uniformly dispersed in the transport mixture fluid even if the proportion of water is high in the transport mixture fluid described later.

<Hydrophobic silica>
In this embodiment, the hydrophobic silica forms an anticorrosion coating with the organic long chain compound adsorbed on the metal surface.
Hydrophobic silica is obtained by surface treatment of a silica surface with a hydrophobic component. Although a silane coupling agent, a polydimethylsiloxane, etc. are raised as a component which surface-treats the silica surface, It does not specifically limit. The hydrophobic silica used in the present embodiment is hard to precipitate even if it is a strongly alkaline solution or a strongly acidic solution in which divalent or trivalent ions are present, since the surface of the hydrophobic silica is previously treated with a hydrophobic component. Distributed uniformly.

The hydrophobic silica preferably has a specific gravity larger than that of water, and the specific gravity to water (4 ° C.) is preferably 1.8 to 2.4, more preferably 2.0 to 2.2. It is. When the specific gravity to water is 1.8 or more, when using the corrosion inhibitor composition of the present invention in the oil production pipe, pipeline, etc. of equipment of production wells such as oil field and gas field where water and crude oil components are mixed. Since the hydrophobic silica tends to sink in the water phase, even in a pipeline or the like having a structure in which oil / water separates, the bottom of the water phase can be protected against corrosion. If the specific gravity to water is 2.4 or less, the amount of precipitated hydrophobic silica can be reduced.

The average particle diameter of the hydrophobic silica is preferably 10 to 15 nm in terms of BET average particle diameter, and more preferably 11 to 12 nm in terms of BET average particle diameter. If the BET average particle size is 10 nm or more, it is possible to disperse the hydrophobic silica in the transport mixed fluid without aggregating, and when it exceeds 15 nm, it is likely to be agglomerated by hydrophobic interaction and secondary agglomerated Is likely to coarsen and precipitate.
The BET average particle size of the hydrophobic silica can be confirmed using the BET method.

Also, the surface hydrophobization ratio of the hydrophobic silica is preferably high, and is preferably 80 to 100%. In the present embodiment, it is more preferable to use hydrophobic silica having a surface hydrophobization rate of 100%. The higher the surface hydrophobization ratio, the more likely it is to show the effect of corrosion prevention.
Although the measuring method of the surface hydrophobization rate of hydrophobic silica is not specifically limited, rough estimation is possible in the contact angle of methanol with respect to a hydrophobic silica surface.

The content of the hydrophobic silica in the corrosion inhibitor composition is preferably 3 to 60 parts by mass, and more preferably 6 to 40 parts by mass with respect to 100 parts by mass of the organic long chain compound. If the content of hydrophobic silica is 3 parts by mass or more, the effect of corrosion prevention is further enhanced. The effect of corrosion prevention tends to increase as the content of hydrophobic silica increases, but when it exceeds 40 parts by mass, the improvement of the effect reaches a plateau. In consideration of the balance between the effect of corrosion prevention and the production cost, the content of the hydrophobic silica is preferably 60 parts by mass or less.

<Organic solvent>
An organic solvent can be used to disperse the hydrophobic silica efficiently.
As will be described later, it is preferable that the transport mixed fluid in the oil collection pipe, pipeline, etc. of the equipment of production wells such as oil fields and gas fields where water and crude oil components are mixed contains the corrosion inhibitor composition of this embodiment. Thus, when the corrosion inhibitor composition of the present embodiment is contained in the transport mixed fluid, the organic solvent is preferably in the liquid phase under the temperature and pressure that are the transport conditions of the transport mixed fluid.
The temperature and pressure of the transport mixed fluid show unique values for each oil well and gas well. As the organic solvent which is liquid phase under the temperature and pressure, hydrocarbon having 8 to 20 carbon atoms, paraffin, cycloparaben, naphtha, light oil, heavy oil, crude oil, and a single aromatic ring in one molecule are mentioned. And aromatic compounds such as cyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons having two or more aromatic rings in one molecule.
As the organic solvent, a single-ring aromatic hydrocarbon is preferable in that it has good compatibility with organic long-chain compounds, can disperse hydrophobic silica highly, and is more likely to exhibit the effect (corrosion prevention) of the present embodiment. Particular preference is given to single ring aromatic hydrocarbons having a boiling point of 60 to 200 ° C. under pressure conditions of 1 MPa. The boiling point of the monocyclic aromatic hydrocarbon is more preferably 70 to 180 ° C., further preferably 80 to 150 ° C. under a pressure condition of 0.1 MPa. On the other hand, the use of the corrosion inhibitor composition at higher temperatures, under high pressure (e.g. temperatures above 100 ° C. and pressures above 10 MPa) (ie production tubes' pipelines and pipelines are at higher temperatures) In the use of the corrosion inhibitor composition under an environment exposed to high pressure), the polycyclic aromatic hydrocarbon is used as the organic solvent in that the effect (corrosion prevention) of the present embodiment is more easily exhibited. It is preferable to use a combination of polycyclic aromatic hydrocarbons and amine compounds such as dodecylamine, stearic acid and oleic imidazoline as organic long chain compounds.

Examples of monocyclic aromatic hydrocarbons include benzene (boiling point 80.1 ° C.), toluene (boiling point 110.6 ° C.), xylene (boiling point 138-144 ° C.), ethylbenzene (boiling point 136 ° C.) and the like. One of these monocyclic aromatic hydrocarbons may be used alone, or two or more thereof may be used in combination.
Examples of polycyclic aromatic hydrocarbons include Solvesso 100, Solvesso 150, and Solvesso 200 manufactured by Exxon Mobil. One of these polycyclic aromatic hydrocarbons may be used alone, or two or more thereof may be used in combination.

The content of the organic solvent in the corrosion inhibitor composition is preferably 100 to 2000 parts by mass, and more preferably 300 to 1500 parts by mass with respect to 100 parts by mass of the organic long chain compound. If the content of the organic solvent is 100 parts by mass or more, an increase in the effect of corrosion prevention by the addition of the organic solvent can be obtained. The effect of preventing corrosion tends to increase as the content of the organic solvent increases, but when it exceeds 2000 parts by mass, the improvement of the effect reaches a plateau. In consideration of the balance between the effect of corrosion prevention and the production cost, the content of the organic solvent is preferably 1000 parts by mass or less.

<Optional component>
The corrosion inhibitor composition of the present embodiment may contain optional components as needed, as long as the effects of the present embodiment are not impaired.
As an optional component, for example, an alcohol having a low molecular weight (specifically, 1 to 10 carbon atoms) such as ethanol can be mentioned. When the corrosion inhibitor composition contains a low molecular weight alcohol, the dispersibility of the organic long chain compound in water is further enhanced.

<Function effect>
The corrosion inhibitor composition of the present embodiment is excellent in corrosion prevention performance because it contains the organic long chain compound and the hydrophobic silica. Moreover, when the corrosion inhibitor composition of the present embodiment contains the organic long chain compound, the hydrophobic silica, and the organic solvent, the corrosion prevention performance is further improved.
In particular, the corrosion inhibitor composition of the present embodiment exhibits an excellent effect on the inner surface of a pipe which is separated from oil and water which is difficult to suppress corrosion with a conventional corrosion inhibitor and which is wet with water. Therefore, with the corrosion inhibitor composition of the present embodiment, it is possible to sufficiently prevent the corrosion of the inner surface of the oil collection pipe and the transport pipe. The reason why the corrosion inhibitor composition of the present embodiment is excellent in corrosion prevention is considered as follows.

For example, when an anticorrosive film is formed on the inner surface of the oil collection pipe by the corrosion inhibitor composition of the present embodiment, an anticorrosive film 12 made of the corrosion inhibitor composition on the inner surface 11a of the main body 11 as shown in FIG. The oil pipe 10 is obtained. Specifically, as schematically shown in FIG. 2, the anticorrosive film 12 is considered to be formed as follows.
First, the polar group of the organic long chain compound is adsorbed on the inner surface 11 a of the main body 11 to form a layer (hereinafter referred to as “layer A”) 12 a mainly composed of the organic long chain compound. Furthermore, hydrophobic silica and an organic solvent are involved in the hydrophobic group of the organic long chain compound. For example, when hydrophobic silica and an organic solvent are charged together, a layer (hereinafter referred to as "B layer") 12b mainly composed of an organic solvent and a layer mainly composed of hydrophobic silica (hereinafter referred to as The layer 12 c is formed on the layer A 12 a to form the anticorrosive film 12. The C layer 12c may be formed on the A layer 12a to form the anticorrosive film 12. In FIG. 2, for the purpose of schematically showing the anticorrosive film 12, the A layer 12a and the B layer are shown. Although a distinction is made between 12b and C layer 12c, the interface between these layers is not clear.
When the A layer 12a, the B layer 12b and the C layer 12c are formed, the polar group of the organic long chain compound is adsorbed to the inner surface 11a of the main body 11 to form the A layer 12a. By the organic solvent being entangled in the hydrophobic group to form the B layer 12b, the anticorrosion effect of the organic long chain compound is enhanced, and the corrosion prevention property is exhibited. When the C layer 12c is formed by further using hydrophobic silica for the organic long-chain compound and the organic solvent, the stability is improved, the corrosion prevention effect is further improved by further enhancing the antirust effect, the oil collection pipe, It is considered that corrosion of the inner surface of the transport pipe can be sufficiently prevented.
When the C layer 12c is formed on the A layer 12a to form the anticorrosive film 12, hydrophobic silica may be entangled in the hydrophobic group of the organic long chain compound to form the C layer 12c. The organic solvent derived from the crude oil component flowing in the main body 11 may be entangled with the hydrophobic silica in the hydrophobic group of the organic long chain compound to form the B layer 12 b and the C layer 12 c.

The corrosion inhibitor composition of the present embodiment is an oil collection pipe of a production well for producing oil, natural gas, etc. in which the inner surface of a transport pipe or the like is exposed to a liquid phase containing wet corrosive gas, oil, natural gas It is suitable as a corrosion inhibitor composition for transport pipes of pipelines for transporting, and is specifically used to form an anticorrosion film on the inner surface of a production pipe or transport pipe.

"Transport mixed fluid"
The transport mixed fluid of the present embodiment is used when forming an anticorrosive coating on a oil collection pipe or a pipeline.
The transport mixed fluid of the present embodiment is a fluid that passes through oil collection pipes, pipelines and the like of facilities of production wells such as oil fields and gas fields where water and crude oil components are mixed, and liquid hydrocarbon fluid and gas phase And at least one hydrocarbon fluid selected from the group consisting of: a hydrocarbon fluid, water, and the corrosion inhibitor composition described above.
The hydrocarbon fluid in the present embodiment includes crude oil as it is mined, natural gas as it is mined, and corrosive gas such as carbon dioxide and hydrogen sulfide.
The water in this embodiment may be ground water as it has been mined, but when crude oil, natural gas, and ground water from the production well cease to be self-injecting, they are introduced into the injection well to promote recovery of the crude oil and natural gas. It may be water to be added.
In the transport mixed fluid of the present embodiment, the corrosion inhibitor composition is such that water is only ground water and the ratio of hydrocarbon fluid which is oil is high (for example, oil (hydrocarbon fluid): water = 95 to 75 parts by mass) Although 5 to 25 parts by mass can be used, it can also be used after addition of water to promote the recovery of crude oil and natural gas Specifically, oil (hydrocarbon fluid): water = 10 to A ratio of 30 parts by mass: 90 to 70 parts by mass can also be used, which is the property of the organic long chain compound in the corrosion inhibitor composition of the present embodiment, the specific gravity and / or the specific gravity of the hydrophobic silica. It is realized by adjustment.

"Method of injecting corrosion inhibitor composition"
In this embodiment, a mixed fluid containing a hydrocarbon fluid and water, a first corrosion inhibitor composition containing an organic long chain compound having a polar group, and a second corrosion inhibitor composition containing hydrophobic silica Charging the corrosion inhibitor composition of The second corrosion inhibitor composition may contain an organic solvent and optional components added as needed. When the second corrosion inhibitor composition contains an organic solvent, the organic solvent and the hydrophobic silica may be mixed in advance to prepare a dispersion.
The order of the first corrosion inhibitor composition and the second corrosion inhibitor composition containing hydrophobic silica is preferably, but not limited to, separately introduced.
It is particularly preferable to introduce the second corrosion inhibitor composition after introducing the first corrosion inhibitor composition, since this improves the efficiency of the formation of the anticorrosive film.

"Well well and pipeline"
The well and pipeline of the present embodiment include a steel pipe having an anticorrosive coating formed on the inner surface by the corrosion inhibitor composition of the present embodiment described above as a production pipe of a production well or as a transport pipe of a pipeline. . The inner surface is the surface on the inner side of the oil production pipe or transport pipe, and is the surface in contact with the crude oil or natural gas containing the wet corrosive gas.
In addition, the outer surfaces of the oil collection pipe and the transport pipe may also be coated with a covering layer as needed.
As a coating layer which coat | covers an outer surface, the thing of the structure where the primer layer, the adhesive bond layer, and the polyolefin layer laminated | stacked sequentially is mentioned from the outer surface side, for example. The primer layer is formed of, for example, an epoxy resin. The polyolefin layer is formed of at least one of polyethylene and polypropylene, and may be a single layer or a plurality of layers.

FIG. 1 is a cross-sectional view showing an example of the oil production pipe included in the well of the present embodiment. As described above, in the oil collection pipe 10 of this example, the anticorrosive film 12 made of the corrosion inhibitor composition is formed on the inner surface 11 a of the main body 11.
The adhesion amount of the organic long chain compound is preferably 0.1 to 3 mg per 1 m ² of the inner surface 11 a of the main body 11.
The coating weight of 1 m ² per hydrophobic silica of the inner surface 11a is 0.4 mg ~ 0.9 g are preferred.
Further, the adhesion amount of the organic solvent is preferably 20 mg to 3 g per 1 m ^{2 of the} inner surface 11 a.
Note that the organic long chain compound per inner surface 1 m ² of the pipeline is the same for adhering amount of the hydrophobic silica and organic solvent.

Here, an example of a method of forming the anticorrosive film 12 on the inner surface 11a of the pipe will be described with reference to FIG. Figure 3 shows an oil field intended for the production of oil. In the oil field, a production well 20 for extracting crude oil from the underground oil reservoir 1, a separator 31 for separating impurities such as natural gas and ground water from untreated crude oil, an oil storage tank 32 for storing crude oil from which impurities are separated, an oil storage tank A pipeline system 34 is provided to transport the crude oil from 32 to the processing facility 33.
FIG. 4 shows the structure of the production well 20 particularly in the oil field. The production well 20 includes a cylindrical casing 21 reaching the oil layer 1 and a tubing 22 as an oil production pipe passed through the inside of the casing 21. A plurality of small holes are formed in the lower end wall surface of the casing 21.
The lower end of the tubing 22 reaching the oil layer 1 is connected with an entry guide 23 for introducing the production fluid into the tubing 22. At the upper end portion of the tubing 22 exposed to the ground, a wellhead device 24 including equipment (not shown) such as a valve, a pressure gauge, a thermometer, and a blowout prevention device is attached.
Connected to the wellhead device 24 are a first tank 25 and a second tank 51 for containing the corrosion inhibitor composition of the present embodiment. From the first tank 25, a first corrosion inhibitor composition containing an organic long chain compound having a polar group is introduced, and from the second tank 51, a second corrosion inhibitor composition containing hydrophobic silica is Introduce. The first tank 25 and the second tank 51 are in communication with the tubing 22 via the injection pipe 26. The inlet tube 26 is provided with a pump 27 which pressure feeds the corrosion inhibitor composition into the interior of the tubing 22.

The crude oil present in the oil reservoir 1 flows from the entry guide 23 into the inside of the tubing 22. When the pressure of the oil reservoir 1 is high, the crude oil is self-injected from the well through the tubing 22, but when the pressure of the oil reservoir 1 is low, the crude oil is pumped to the ground using a not shown pumping pump or the like. The crude oil mined from the oil reservoir 1 through the tubing 22 is transported to the separator 31 through the wellhead device 24, separated from impurities, temporarily stored in the oil storage tank 32, and thereafter stored in the processing facility 33 through the pipeline system 34. It is transported.

Methods of forming an anticorrosive coating on the inner surface of the tubing 22 with a corrosion inhibitor composition include a method in which production of crude oil is temporarily stopped and a method in which production of crude oil is continued.
First, the method of stopping the production of crude oil and forming the anticorrosive coating will be described. The valve of the wellhead device 24 is closed, and the inside of the tubing 22 is a closed space excluding the portion of the entry guide 23 at the tip. Inside the tubing 22 that has become a closed space, crude oil as it is mined, which contains natural gas, ground water, and corrosive gases such as carbon dioxide and hydrogen sulfide, is sealed. While maintaining this state, the pump 27 is operated to inject the corrosion inhibitor composition into the inside of the tubing 22. In the production well where the pressure of the oil layer 1 is high and the crude oil is self-injecting, the corrosion inhibitor composition is pressurized and injected into the inside of the tubing 22 at a pressure higher than that of the oil layer 1 while maintaining the tightness of the tubing 22.
In a production well where the pressure of the oil layer 1 is low and no crude oil is injected by itself, the corrosion inhibitor composition may be supplied to the inside of the tubing 22 with the valve of the wellhead device 24 open.

The corrosion inhibitor composition supplied to the inside of the tubing 22 precipitates the inside of the tubing 22, and in the process the components of the organic long chain compound, the organic solvent and the hydrophobic silica adhere to the inside surface of the tubing 22 Thus, the anticorrosion coating 12 is formed which is composed of the A layer 12a, the B layer 12b and the C layer 12c shown in FIG.

Next, a method of forming an anticorrosion film on the inner surface of the tubing 22 while continuing the production of crude oil will be described. As shown in FIG. 5, the inside of the tubing 22 has a sufficient length for the tip to reach the entry guide 23. With the injection pipe (capillary tube) 26 having a stem attached, the pump 27 is operated to supply the corrosion inhibitor composition to the inside of the tubing 22 as required.
The corrosion inhibitor composition is injected into the inside of the tubing 22 from the tip of the injection pipe 26 which reaches the entry guide 23, and flows through the inside of the tubing 22 with the crude oil going from the oil layer 1 to the ground, and in the process the inner surface of the tubing 22 The components of the organic long-chain compound, the organic solvent and the hydrophobic silica adhere to the above to form an anticorrosive film 12 composed of the A layer 12a, the B layer 12b and the C layer 12c shown in FIG.
By the above method, the anticorrosive coating 12 can be formed on the inner surface of the existing tubing 22 in the production well.

In the case of forming an anticorrosive film on the inner surface of the pipeline, for example, the following is performed.
FIG. 6 shows a pipeline system 34 for transporting crude oil from the wellhead apparatus 24 to the processing facility 33 (see FIG. 3) via the separator 31 and the oil storage tank 32. The pipeline system 34 includes a pumping facility 35 for pumping crude oil temporarily stored in an oil storage tank toward a refinery, a pipeline 36 connected with a large number of transport pipes, and crude oil pumped through the pipeline 36 to the refinery And a receiving facility 37 for receiving.
On the other hand, the wellhead device 24 is connected to a first tank 25 and a second tank 51 for containing the corrosion inhibitor composition. The first tank 25 and the second tank 51 are connected to the wellhead device 24 via the injection pipe 26 and are in communication with the pipeline 36 via the separator 31 and the oil storage tank 32. The inlet pipe 26 is provided with a pump 27 for pressure feeding the corrosion inhibitor composition into the interior of the pipeline 36 through the wellhead device 24.

When forming an anticorrosive film on the inner surface of the pipeline 36 with the corrosion inhibitor composition, the pump 27 is operated to inject the corrosion inhibitor composition into the interior of the pipeline 36 through the wellhead device 24, whereby the corrosion inhibitor composition is formed. The crude oil flows through the inside of the pipeline 36 together with the crude oil, and in the process, the components of the organic long-chain compound, the organic solvent and the hydrophobic silica adhere to the inner surface of the pipeline 36, and the A layer 12a shown in FIG. , The B layer 12 b and the C layer 12 c are formed.
According to the above-described method, the anticorrosive film 12 can be formed on the inner surface of the transport pipe constituting the existing pipeline 36.

The well and pipeline of the present embodiment described above are resistant to corrosion because the anticorrosive coating is formed by the corrosion inhibitor composition of the present embodiment on the inner surface of the tubing and pipeline.
Further, in the present embodiment, after the anticorrosive film is formed on the inner surface of the tubing and the pipeline, the flow of the corrosion inhibitor composition may be stopped to flow the crude oil or the natural gas containing the wet corrosive gas.
That is, since the corrosion inhibitor composition of the present embodiment forms an anticorrosion film, the corrosion inhibitor composition is distributed throughout the operation of oil production pipes and pipelines of production well equipment such as oil fields and gas fields. There is no need to

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

"Test 1"
Example 1
The corrosion rate was measured using the apparatus 40 shown in FIG.
The apparatus 40 shown in FIG. 7 includes a sealable glass container 41 (glass cell) having a capacity of 1.0 L, an addition means 42 for adding a reagent to the glass container 41, and a gas such as carbon dioxide to the glass cell 41. It comprises injection means 43 for injection, discharge means 44 for discharging gas from the glass cell 41, an electrode 45 and stirring means 46.
A heater 41 a is attached to the outer periphery of the glass cell 41 so that the temperature of the solution contained in the glass cell 41 can be kept constant.
The electrode 45 includes a reference electrode 45a, a working electrode 45b, and a counter electrode 45c. In this example, a carbon steel electrode was used as the reference electrode 45a and the working electrode 45b, and platinum was used as the counter electrode 45c.

Sodium bicarbonate is added to 500 mL of an aqueous sodium chloride solution having a concentration of 1% by mass so that the concentration is 400 mg / L, and hydrochloric acid is added so that the pH at room temperature (25 ° C.) is 3.9. , Prepared test water.
The entire amount of test water obtained is put into the glass cell 41, and while stirring in an open state, a minute current is flowed between the reference electrode 45a and the working electrode 45b to set the potential difference between the electrodes to a predetermined set potential (10 mV) The current density flowing between the working electrode 45b and the counter electrode 45c was measured.
Control of the potential was performed by sweeping from the corrosion potential to the anode side at a constant potential sweep rate.
The corrosion rate was determined by the polarization resistance method based on the results of the obtained potential and current density. This was taken as the corrosion rate (r ₀ ) at the time of blanking. The corrosion rate (r ₀ ) at the time of blanking was 44 mpy.

Separately, the same amount of test water is put in a glass cell 41, and a first corrosion inhibitor composition containing an organic long chain compound, and a second corrosion inhibitor composition containing an organic solvent and hydrophobic silica, The corrosion rate (r ₁ ) per addition of the corrosion inhibitor composition was determined in the same manner as the corrosion rate (r ₀ ) while separately adding from the addition means 42 and stirring in the open state.
The corrosion rate after blanking (that is, before adding the corrosion inhibitor) is 0%, and from the corrosion rate (r ₀ ) and the corrosion rate (r ₁ ), after adding the corrosion inhibitor according to the following formula (1) The corrosion protection rate was determined. The results are shown in FIG.
Corrosion protection rate (%) = {(r ₀ −r ₁ ) / r ₀ } × 100 (1)
Note that laurylamine (concentration: 2 × 10 ^-4 mol / L, specific gravity to water: 0.8) is used as an organic long chain compound, and xylene is used as an organic solvent, and organosilica sol (TOL manufactured by Nissan Chemical Industries, Ltd. as hydrophobic silica) -ST, (BET average particle size: 10 to 15 nm, surface hydrophobization ratio: 100%, specific gravity to water: 2.2) was used.
Specifically, first, the corrosion rate (r ₁ ) was determined by adding 37 mg of laurylamine (concentration: 2 × 10 ⁻⁴ mol / L) only, and the corrosion resistance was calculated. The corrosion resistance was 32% when only laurylamine was added.
Next, the corrosion rate (r ₁ ) was determined by adding 2 mg of organosilica sol to 0.1 cc (80 mg) of xylene, and the corrosion resistance was calculated. The anticorrosion rate at this time was 32%.
Furthermore, 0.1 cc (80 mg) of xylene and 2 mg of organosilica sol are added stepwise, and (organo silica sol (mg) / xylene (cc)) = 4 mg / 0.2 cc, 6 mg / 0.3 cc, 8 mg / 0. The corrosion rate (r ₁ ) was determined at 4 cc, 10 mg / 0.5 cc, 12 mg / 0.6 cc, and 14 mg / 0.7 cc, respectively, to calculate the corrosion resistance.
The corrosion protection rates are 56%, 66%, 80%, 86%, 89% and 91% in order, and the results are shown in FIG.
In Example 1, 5 parts by mass of the hydrophobic silica is added stepwise with respect to 100 parts by mass of the organic long chain compound, and 220 parts by mass of the organic solvent is added stepwise.

(Comparative example 1)
First, 37 mg of laurylamine (concentration: 2 × 10 ^-4 mol / L) was added in the same manner as in Example 1.
Thereafter, instead of the corrosion inhibitor composition of the present invention, the corrosion rate (r ₁ ) when adding only the organic solvent xylene as 0.2 cc, 0.4 cc, 0.6 cc, 0.7 cc stepwise The corrosion resistance was calculated.
The corrosion protection rates are 36%, 59%, 62% and 64% in order, and the results are shown in FIG.
In Comparative Example 1, 440 parts by mass of the organic solvent is added stepwise with respect to 100 parts by mass of the organic long chain compound.

As is clear from the results of FIG. 8, in Example 1, the corrosion inhibitor ratio is about 90% as compared with that before the addition of the corrosion inhibitor composition (blank) by adding the corrosion inhibitor composition of the present invention It rose to From this result, although the corrosion inhibitor composition of the present invention is a component that is easily dispersed in a hydrophobic hydrocarbon fluid, it also disperses in water and prevents corrosion against a wet corrosive gas containing carbon dioxide and the like. It was shown to exert an effect.
On the other hand, in Comparative Example 1, although the degree of corrosion resistance increased (about 65%) to a certain extent by adding laurylamine which is an organic long-chain compound and xylene which is an organic solvent, it is inferior to Example 1. there were.

According to the corrosion inhibitor composition of the present invention, in the production wells of oil fields, gas fields, etc., members exposed to the liquid phase containing the wet corrosive gas, such as the oil production pipes of production wells and transport pipes of pipelines. Corrosion can be sufficiently prevented. Moreover, according to the corrosion inhibitor composition of the present invention, in the production well of an oil field, gas field, etc., the content ratio of water, for example, in the transport mixed fluid passing through the oil production pipe of the production well, the transport pipe of the pipeline, etc. It is possible to show the effect of preventing corrosion against wet corrosive gases even if

10 oil production pipe 11 main body 12 anticorrosion film 20 production well 22 tubing (oil production pipe)
23 Entry Guide 34 Pipeline System 36 Pipeline (Transportation Pipe)

Claims (12)

1. A corrosion inhibitor composition comprising an organic long chain compound having a polar group and a hydrophobic silica.
2. The corrosion inhibitor composition according to claim 1, further comprising an organic solvent.
3. At least one hydrocarbon fluid selected from the group consisting of liquid hydrocarbon fluid and gaseous hydrocarbon fluid;
   water and,
   What is claimed is: 1. A transport mixed fluid comprising: a long chain organic compound having a polar group; and a corrosion inhibitor composition containing hydrophobic silica.
4. The transport mixed fluid according to claim 3, wherein the organic long chain compound having a polar group has one or more selected from nitrogen, oxygen, and sulfur.
5. 5. A transport mixed fluid according to claim 3 or 4, wherein the corrosion inhibitor composition further comprises an organic solvent.
6. The transport mixture fluid according to claim 5, wherein the organic solvent is a liquid phase under temperature and pressure which are transport conditions of the transport mixture fluid.
7. The transport mixed fluid according to claim 5 or 6, wherein the organic solvent is an aromatic compound.
8. A method of injecting a corrosion inhibitor composition, comprising
   Corrosion inhibitor composition for introducing a corrosion inhibitor composition into a mixed fluid comprising water and at least one hydrocarbon fluid selected from the group consisting of liquid phase hydrocarbon fluid and gaseous phase hydrocarbon fluid Have a product input process,
   The corrosion inhibitor composition comprises a first corrosion inhibitor composition containing an organic long chain compound having a polar group and a second corrosion inhibitor composition containing a hydrophobic silica. Do.
9. 9. The method of claim 8, wherein the second corrosion inhibitor composition further comprises an organic solvent.
10. 10. The method according to claim 8, wherein the corrosion inhibitor composition charging step comprises charging the first corrosion inhibitor composition and the second corrosion inhibitor composition separately to the mixed fluid. Method of introducing the corrosion inhibitor composition described.
11. A well comprising a tubing having an anticorrosive coating formed on the inner surface by the corrosion inhibitor composition according to claim 1 or 2.
12. A pipeline comprising a transport pipe having an anticorrosive film formed on an inner surface thereof by the corrosion inhibitor composition according to claim 1 or 2.

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