RU2754324C1 - Method for obtaining bis-imidazolines and their derivatives based on tetraethylenepentamines for corrosion protection of oilfield equipment and pipelines - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of protection of gas and oil field equipment and pipelines operating in hydrogen sulfide-containing highly mineralized aqueous media, from corrosion and hydrogen absorption, as well as during the transportation of oil and gas. The method involves the interaction of polyethylene polyamine and carboxylic acid with distillation of reaction water and impurities, while tetraethylenepentamine is used as polyethylene polyamine, which interacts with monocarboxylic acid, which is used as 2-ethylhexanoic or oleic acid, first at a temperature of 145-155°C for 4.0-5.5 h, then at 255°C for 2h in a molar ratio of tetraethylenepentamine : monocarboxylic acid equal to 1 : 2, followed by the reaction of the obtained bis-imidazoline with benzyl chloride at a temperature of 90°C.

EFFECT: invention expands of the raw material base and range of corrosion inhibitors.

1 cl, 1 tbl, 2 ex

Description

The invention relates to the field of protection of gas and oil field equipment and pipelines operating in hydrogen sulfide-containing highly mineralized aqueous media from corrosion and hydrogen absorption, as well as during the transportation of oil and gas.

Known corrosion inhibitor used in

hydrogen sulfide-containing media, which contains the product of the interaction of 1 mol of fatty acid with the number of carbon atoms C ₁₀ -C ₂₀ and (0.1-1) mol of aminoparaffin with the number of carbon atoms C ₈ -C ₂₀ with the following ratio of components, wt. %:

the product of the interaction of 1 mol of fatty acid with the number of carbon atoms C ₁₀ -C ₂₀ and (0.1-1) mol of aminoparaffin with the number of carbon atoms C ₈ -C ₂₀ - 10-50;

nonionic surfactant - 10-30;

the solvent is the rest (A.c. # 2061091, C23F 11 / 00.1996).

The disadvantage of using the known corrosion inhibitor is a relatively low protective effect (87-94%) at a dosage of 50 mg / l. Another disadvantage is the use of a poisonous substance - methanol, the latter has a low boiling point and is used in an amount of 80 mg per 10 g of active base and it is impossible to establish the conditions for the interaction of fatty acid and aminoparaffin from the description.

Known inhibitor of hydrogen sulfide corrosion, consisting of a mixture of hydrochloride aminoparaffins (AS No. 652316, E21B 43 / 00,1979). The disadvantage of the known inhibitor is its low effect at a dosage of up to 100 mg / l.

The objective of the invention is to develop a method for producing corrosion inhibitors that provide effective protection of metals of gas and oil field equipment, pipelines from corrosion.

The technical result when using the invention is expressed in the expansion of the raw material base and the range of corrosion inhibitors. Also, the result of the invention is a reduction in the cost of the final product.

The problem is solved by the claimed method of producing corrosion inhibitors for the protection of gas and oil field equipment and pipelines based on polyethylene polyamines and carboxylic acids, with distillation of reaction water and impurities. Tetraethylenepentamine (TEPA) is used as polyethylene polyamines, which interacts with monocarboxylic acids, which are 2-ethylhexanoic (Ehexan.k.) Or oleic (OLC) acids, first at a temperature of 145-155 ° C for 4, 5-5.5 h, then at 255 ° C for 2 h in a molar ratio of TEPA: monocarboxylic acids equal to 1: 2, followed by the interaction of the obtained bis-imidazolines with benzyl chloride at a temperature of 90 ° C.

The above result of obtaining corrosion inhibitors operating in mineralized and hydrogen sulfide-containing environments is achieved by the feature that TEPA interacts with 2-ethylhexanoic (Ehexan.k.) Or oleic (Ol.k.) acids first at a temperature of 145-155 ° C for 4.5-5.5 h, then at 255 ° C for 2 h in a molar ratio of TEPA: acid = 1: 2 with the formation of bis-imidazolines (1):

R = C ₇ H ₁₅ , C ₁₇ H ₃₃ .

The obtained bis-imidazolines (1) interact with benzyl chloride (BC) at a temperature of 90 ° C in a molar ratio of bis-imidazoline (1): BC = 1: 1 for 4-4.5 h.

The essence of the invention is illustrated by the following examples.

Example 1. In a reactor with a stirring device, a thermometer, a refrigerator and a dropping funnel, 18.9 g (0.1 mol) of tetraethylenepentamine (TEPA) and 28.8 g (0.2 mol) of 2-ethylhexanoic acid (Ehexan.k. ) in the molar ratio of TEPA: Ehexan.c. = 1: 2. The reaction mixture is heated first at a temperature of 145 ° C for 4.5 hours, then at a temperature of 255 ° C for 2 hours, and the reaction water and impurities contained in the starting products are continuously distilled off.

39.04 g (96.4%) of bis-imidazoline (2) are obtained.

Found,%: N 16.94. C ₂₄ H ₄₇ N _5. Calculated,%: N 17.28.

The resulting compound (2) 40.5 (0.1 mol) interacts with 12.65 g (0.1 mol) of benzyl chloride (BC) at a temperature of 90 ° C for 4 h in a molar ratio of compound (2): BC = 1 :1.

51.30 g (95.9%) of N-benzyl bis (imidazoline) chloride (3) are obtained.

Found,%: N 12.74. C ₃₁ H ₅₄ N ₆ Cl. Calculated,%: N 13.17.

Example 2. Under the conditions of example 1, 18.9 g (0.1 mol) of TEPA and 56.4 g (0.2 mol) of oleic acid (Ol.k.) are loaded into the reactor in a molar ratio of TEPA: Ol.k. = 1: 2. The reaction mixture is heated first at a temperature of 155 ° C for 5.5 hours, then at a temperature of 255 ° C for 2 hours, and the reaction water and impurities contained in the starting products are continuously distilled off.

66.94 g (98.3%) of bis-imidazoline (4) are obtained.

Found,%: N 9.56. C ₄₆ H ₈₃ N ₅ . Calculated,%: N 9.92.

The resulting compound (4) 68.1 (0.1 mol) interacts with 12.65 g (0.1 mol) BC at a temperature of 90 ° C for 4.5 h in a molar ratio of bis-imidazoline (4): BC = 1: 1.

78.0 g (96.6%) of N-benzyl bis (imidazoline) chloride (5) are obtained.

Found,%: N 9.06. C ₅₁ H ₉₀ N ₅ Cl. Calculated,%: N 9.49.

where R = H (4), (HC1) CH ₂ H ₅ C ₆ (5)

Examples 1-2 confirm the high yield of bis-imidazolines - 95.9-98.3%, as well as a high protective effect - 96.9-99.2%, provided that the declared parameters of the production process are maintained.

Subject to the deviation of the declared parameters of the process of obtaining bis-imidazolines and their derivatives, heating the reaction mixture of tetraethylenepentamine and ethylhexanoic acid at a temperature of 125 ° C for 1.5 h demonstrates a decrease in the yield of the product, as well as a decrease in the protective effect.

Claims (2)

1. A method of producing corrosion inhibitors for oilfield, mineralized and hydrogen sulfide-containing media based on polyethylene polyamines and carboxylic acids with distillation of reaction water and impurities, characterized in that tetraethylene pentamine is used as polyethylene polyamine, which interacts with monocarboxylic acid first at a temperature of 145-155 ° C in for 4.0-5.5 h, then at 255 ° C for 2 h in a molar ratio of tetraethylenepentamine: monocarboxylic acid equal to 1: 2, followed by the interaction of the resulting bis-imidazoline with benzyl chloride at a temperature of 90 ° C. 2. The method according to claim 1, characterized in that 2-ethylhexanoic or oleic acid is used as the monocarboxylic acid.