RU2255102C1 - Composition for preservation of metallic objects, especially oil- field equipment, during in-process storage and transportation - Google Patents

Abstract

FIELD: corrosion protection.

SUBSTANCE: invention is designed for oil production and can also be used in mechanical engineering, instrumentation engineering, and other branches. Composition contains 6-10% low-grade lignosulfonates, 2-5% industrial oil (spindle oil, tall oil, or MS-20 oil), 60-65% production waste, and 24-28% additive, namely primary C₈-C₁₁-amines. Production waste is, in particular, vat residues from production of synthetic fatty C₁₀-C-acids or solid petroleum hydrocarbons: asphaltene-tar-paraffin deposits formed during production and transportation of petroleum. Use of composition increases degree of protection of metallic objects against corrosion under atmospheric precipitate conditions owing to retained high adhesion of coating formed from composition to metal, reduced porosity of coating, and prolonged period of time before appearance of the first center of corrosion attack at lower thickness of coating.

EFFECT: improved anticorrosion characteristics, simplified composition preparation technology, reduced coating formation time, and reduced expenses due to utilized waste.

2 cl, 2 tbl

Description

The invention relates to the field of protection of metals from corrosion, in particular to compositions forming washable film coatings on a steel surface and intended to protect products from ferrous and non-ferrous metals from environmental influences during their interoperational storage and during transportation. The primary area of use is protection against atmospheric corrosion of oilfield equipment parts. The invention can also be used in engineering, instrument-making and other industries.

The known composition "Oremin", recommended by GOST 9.014-78 as a washable film coating for the protection (preservation) of products from ferrous and non-ferrous metals during storage and transportation. The composition is a solution of sodium stearate in hydrocarbon solvents, i.e. contains toxic and fire hazardous components. Before applying to the product, a known composition requires heating up to at least + 80 ° C in order to achieve working viscosity. In addition, it is necessary to prepare the surface of the product - drying, rust removal to obtain a high-quality coating and to prevent the manifestation of film corrosion. All this greatly complicates the technological scheme of inhibition - protection. After applying to the metal, the protective coating obtained from the specified known composition is a semi-solid waxy film that can be easily removed even with little mechanical effort.

Also known is a composition for corrosion protection of metal products during the period of interoperational and long-term storage, containing, wt.%: Multifunctional additive 5.1-5.4 and inhibited water-wax emulsion IVS 706M - the rest. Moreover, the multifunctional additive contains, wt.%: VAT residues of the production of synthetic fatty acids (COSFA) 1.0-1.1; microcrystalline cellulose 1.71-2.79 or methyl cellulose 0.1-0.11; the product of the interaction of cyclohexylamine with synthetic fatty acids of the fraction C ₁₀ -C ₁₃ 1.29-1.30 (Application for IZ No. 95112614, CL 09 D 191/06, publ. 1997).

The main disadvantage of this known composition, as well as for the Oremin composition, is, first of all, the low physical and mechanical properties of the coating formed after applying the known composition to a metal surface.

The closest in technical essence to the proposed composition is a protective coating of a composition comprising the following ingredients, wt.%: Technical lignosulfonates 10-15; tall pitch 45-70, tall oil 2-7; rosin or petrolatum 7-45; xylene 40-66; aluminum powder 0.8-2.0 (ed. certificate of the USSR No. 1732677, class C 09 D 5/08, from 1989).

The specified protective coating is applied to the soil layer, which, in turn, is directly applied to the surface of metal products (possibly the presence of rust). Known coating is used to protect steel products from corrosion in an atmosphere of chlorine, sulfur dioxide and air.

The disadvantage of this known coating, as in the case of the composition "Oremin", is the need at the stage of preparation of the composition of the use of large quantities of toxic and flammable organic solvents (for example, up to 66% xylene) and the obligatory use of high temperature (up to 100 ° C) to obtain mixtures of the necessary viscosity and uniformity.

In addition, certain ingredients of this coating are scarce and expensive (in particular, tall oil pitch and tall oil are specific pulp and paper by-products).

In addition, the known coating is characterized by insufficient resistance to atmospheric precipitation (rain, wet snow), which is manifested in the rapid appearance of foci of corrosion on the metal even with a short exposure of products with a known coating in the open air.

The technical result provided by the proposed composition is to increase the degree of protection of metal products from corrosion under the influence of atmospheric precipitation by maintaining in these conditions high adhesion formed from the claimed coating composition to the metal, reducing the porosity of the coating, increasing the time period until the appearance of the first focus of corrosion, while reducing the thickness of the coating.

An additional technical result is the simplification of the preparation technology of the claimed composition and the reduction of time to obtain coverage.

Another additional technical result is the disposal of waste products incidentally extracted together with oil - asphaltene-tar-paraffin deposits (paraffin deposits).

The specified technical result is achieved by the proposed composition for the preservation of metal products, mainly oilfield equipment, during interoperational storage and transportation, including technical lignosulfonates, industrial oil, production waste and additive, while the composition contains production waste of synthetic fatty acids of fraction C ₁₀ - C ₁₇ KOSZHK oil or solid hydrocarbons - asfaltenosmoloparafinovye deposition AFS, wastes resulting from the production and transportation costs Rovkov oil and an additive composition comprising primary amines C ₈ -C _11, with the following ratio of ingredients, wt.%:

Technical lignosulfonates 6-10

KOSZHK or AFS 60-65

Primary amines C ₈ -C ₁₁ 24-28

Industrial oil 2-5

As an industrial oil, the proposed composition contains spindle oil, tall oil or oil brand MS-20.

When using the proposed composition there is no need for preliminary application of the primer layer as in the prototype, because water-soluble lignosulfonates absorb moisture present on the metal surface, and a mixture of amines with a high pH level (~ 12-13) is a rust modifier and at the same time provides a high degree of adhesion of the coating to the metal.

Using as the basis of the proposed composition KOSZHK or ASPO allows you to get on the metal surface a dense non-porous film, impervious to the effects of corrosive components present in atmospheric conditions.

And industrial oil provides the elasticity of the resulting coating.

The proposed composition was obtained and tested in laboratory conditions. The following substances were used for its preparation:

- Technical lignosulfonates (LST) (OST 13-183-83) grade (A) with a solids content of 47%, a mass fraction of ash to a mass fraction of solids of 16%, a density of 1.23 g / cm ³ and with a content of hydroxyl groups 1 , 1%, carbonyl groups 0.7%, methoxyl groups 11%, high molecular weight fraction 36.3%, medium molecular weight fraction 30.2%, low molecular weight fraction 33.5%;

- KOSZHK (TU 2499-002-24211256-94) is a waste product of the production of synthetic fatty acids of fraction C ₁₀ -C ₁₇ (grade A). They are a mixture of tar and fatty acids with unsaponifiable substances. In the examples, CFCFA is used in the form of a brown waxy mass, the acid number of which is not more than 140 mg KOH / g, the proportion of unsaponifiable substances is 67%, and resin acids 10%. Softening point 40 ° C;

- Paraffin deposits are waste in the extraction and transportation of oil, they are obtained under certain conditions by deposition on the walls of pipelines and oil equipment, making it difficult to complete the process. After mechanical cleaning of the equipment, paraffin deposits are stored in sludge collectors. They are a mixture of solid paraffin wax, asphaltenes and resins. In the examples, the use of paraffin wax with a paraffin content of up to 80%, resins up to 5%, asphaltenes up to 8%. Softening point -27 ° C;

- Primary amines of fraction C ₈ -C ₁₁ are produced according to TU 2516-001-33671256-93. They are a dark brown liquid;

- Industrial oils:

- spindle oil (TU 38.1011232-89), which is a viscous liquid - a mixture of hydrocarbons - light brown in color, designed to lubricate bearings, high-speed spindles of metalworking machines, etc. Kinematic viscosity of oil - 15-20 cSt;

- tall oil according to TU 13-00281074-26-95;

- brand oil MS-20 (MS-8) according to GOST 21743-76.

The inventive composition was prepared as follows.

Example 1. To obtain the composition in laboratory conditions, 33 g of primary amines C ₈ -C ₁₁ were taken and heated in a water bath to a temperature of + 40-50 ° C. Then, 56 g of CFCFA was introduced into them and mixed until completely dissolved. After cooling the resulting mixture to room temperature, 7 g of LCF and 4 g of spindle oil were added to it. Got a composition, which is a homogeneous liquid of dark brown color, with the following ratio of ingredients, wt.%:

LST 7

Primary amines C ₈ -C ₁₁ 33

KOSJK 56

Spindle Oil 4

Example 2. To obtain the composition in laboratory conditions, 22 g of primary amines C ₈ -C ₁₁ were taken, heated in a water bath to a temperature of + 40-50 ° C. Then they introduced 61 g of paraffin and mixed until completely dissolved. After cooling the resulting mixture to room temperature, 9 g of LCF and 8 g of tall oil were added to it. Got a composition, which is a homogeneous liquid of dark brown color, with the following ratio of ingredients, wt.%:

LST 9

Primary amines C ₈ -C ₁₁ 22

AFS 61

Tall oil 8

Compositions with different ingredients were prepared in a similar manner.

Application of the proposed composition on the surface of metal products was carried out as follows: by dipping, or by brush, roller or pneumatic spraying in one layer in such an amount that the film thickness was 35-90 microns (depending on the application method). Next, the products were dried in air for 20-45 min, depending on the thickness of the deposited film and the ambient temperature. As a result, a hard lacquer film was obtained on the surface of the processed products (adhesion of 1-2 points by the method of lattice cuts).

The criterion for the reliability of protection when using weather-resistant coatings according to GOST 9.014-78 is the appearance after testing the minimum number of corrosion centers on the metal while maintaining such coating parameters as appearance, adhesion to metal, film elasticity. Testing of the coating obtained from the proposed composition was carried out according to GOST 9.054-75 in a G-4 thermoclimatic chamber in an atmosphere of salt fog and 100% moist air. Test temperature 40 ± 1 ° C; the total test duration was 336 hours. For comparison, under the same conditions we tested the coating of gun grease (GOST 19537-83), recommended by GOST 9.014-78 for the protection of ferrous metal products from atmospheric corrosion, as well as the coating obtained from the prototype composition. The results are presented in table 1.

Given that the storage conditions of metal products treated with the proposed composition, suggest their storage, including in the open air, under intense exposure to atmospheric precipitation (rain, snow), full-scale tests of the coating obtained from the inventive composition were given.

Field tests were carried out according to GOST 9.039-74 in the winter period of time. The test duration is 90 days. Samples were placed on a bench in the open air (exposure to precipitation - snow, wet snow, air humidity during the test period - 70-90%, temperature - up to -15 ° C), as well as in an unheated room (air humidity - 80%, temperature - up to minus 10 ° С). The test results are shown in table 2.

Studies have shown that the coating obtained from the proposed composition, as well as the coating of the prototype, is characterized by high stability under conditions of exposure to humid air and salt spray. However, under the influence of atmospheric precipitation (rain, snow) in the open air, a coating obtained from the inventive composition has the following advantages over the coating of the prototype:

- the adhesion index under these conditions is 1.5-2 times higher;

- the porosity after testing is an extremely small value of 2-3 pcs / cm ² , while the prototype has 30% of the coating area;

- the first center of corrosion appears only after 60 days of testing, while the prototype - after 20 days;

- and at the same time, the area of corrosion damage after 90 days in the proposed composition is only 10%, while in the prototype - 80%.

Along with the indicated advantages in properties, there are also advantages in the technology for producing a coating from the proposed composition:

- decreases the temperature at which the preparation of the proposed composition;

- the drying period of the coating is reduced by 20-40 times.

Due to these advantages, the use of the inventive composition for the conservation of oilfield equipment and other metal products will ensure their high-quality corrosion protection both when stored indoors and outdoors in the presence of precipitation, and, in addition, will protect them during transportation.

At the same time, due to the fact that the coating obtained from the proposed composition is washable, clogging of submersible pumps and other equipment operating in the well eliminates fragments of a dissolving coating obtained from the proposed composition.

In addition, it becomes possible to dispose of waste generated during the extraction and transportation of oil.

Claims (2)

1. Composition for the preservation of metal products, mainly oilfield equipment, during interoperational storage and transportation, including technical lignosulfonates, industrial oil, production waste and an additive, characterized in that the composition contains production waste of synthetic fatty acids of fraction C ₁₀ -C as production waste ₁₇ KOSZHK oil or solid hydrocarbons - asfaltenosmoloparafinovye deposition AFS, wastes resulting from the production and transportation of oil and an additive composition contains um amines primary C ₈ -C _11, with the following ratio of ingredients, wt.%: Technical lignosulfonates 6-10 KOSZHK or AFS 60-65 Primary amines C ₈ -C ₁₁ 24-28 Industrial oil 2-5. 2. The composition according to claim 1, characterized in that, as an industrial oil, the composition contains spindle oil, tall oil or oil brand MS-20.