CZ2010869A3 - Corrosion inhibitor for natural gas recovery, transportation and storage facility - Google Patents

Abstract

The corrosion inhibitor of the natural gas extraction, transport and storage equipment comprises 45 to 55 wt. % propargyl alcohol, 23 to 27 wt. % dimethylbenzyl laurylammonium bromide, 20 to 26 wt. % triethanolamine phosphate and 0.5 to 1.0 wt. fatty acid alkanolamide. In a more corrosive environment, the inhibitor further comprises 0.2 to 0.5 wt. % of ethanolamine, and optionally 0.2 to 0.5 wt. of octadecylamine as a 10% emulsion.

Description

Technical field

In the extraction of oil, the accompanying medium is often water with higher salinity, carbon dioxide, a mixture of gases of different composition with an admixture of sulphane and often it is a so-called natural gas, which is essentially methane, whose quantities are huge. These amounts of natural gas represent an extraordinary energy supply and are distributed throughout the world by pipelines, liquefied natural gas is transported in tankers and natural gas is also stored in underground storage facilities.

By its chemical composition, the accompanying substances create different pH of natural gas, which in the end can also represent a corrosive environment, which is removed or minimized by scrubbing the natural gas immediately after extraction, for example with a mixture of amino alcohols. However, a small proportion of the aggressive corrosive substances remain in the gas. They are mostly various sulfur compounds, and together with moisture in the gas can corrode the inner surfaces of the gas pipelines.

BACKGROUND OF THE INVENTION

At present, the inner surface of pipelines is generally protected by additives that slow down corrosion processes, maintain alkaline pH, but do not comprehensively cover the entire range of possible corrosion attacks, despite the fact that a certain amount of water always collects .

Some natural gas compositions that exhibit certain amounts of carbon dioxide that affect the environment in terms of lowering the pH to the acidic region need to be added to the gas mixture with effective acidic inhibitors. This is not yet the case and rather alkalizing agents are used to neutralize the acidic environment. Furthermore, the question of microbial corrosion that may accompany gas transport is not solved.

SUMMARY OF THE INVENTION

In order to prevent corrosion of gas pipelines which, due to the occasional water environment and the composition of the transported gas, which may contain acidic components (sulphate, carbon dioxide), can lead to dangerous pitting, the corrosion inhibitor of the natural gas extraction, transport and storage % to 55 wt.% propargyl alcohol, 23 to 27 wt. % dimethylbenzyllaurylammonium bromide, 20 to 26 wt.% triethanolamine phosphate, and 0.5 to 1.0 wt. fatty acid alkanolamide. In a more corrosive environment, the inhibitor further comprises 0.2 to 0.5 wt% ethanolamines, and optionally 0.2 to 0.5 wt% octadecylamine in the form of a 10% emulsion.

Propargyl alcohol is a very effective corrosion inhibitor in acidic environments and, in addition, there is evidence of its partial polymerisation on the metal surface, which enhances corrosion protection. Dimethylbenzyllaurylammonium bromide, which is an effective bactericidal agent, has also been incorporated into the inhibitor composition.

A fatty acid alkanolamide detergent that improves the transport of inhibitors to the liquid / solid phase interface closes the composition of the proposed corrosion inhibitor for the extraction, transport and storage of natural gas.

DETAILED DESCRIPTION OF THE INVENTION

20 ml of distilled water was metered into a 500 ml autoclave and 100 g / l Nm ³ was added to the gas phase of natural gas (N m ³ is normal m ³ at standard conditions of 0 ° C and 0.1 MPa). Then, a mixture of inhibitory substances at a total concentration of 10 mg / l Nm ³ was added to the autoclave. The mixture contained 5%. % propargyl alcohol, 2 wt. % dimethylbenzyllaurylammonium bromide, 24% by weight of riethanolamine phosphate and 0.5% by weight of dimethylbenzyllaurylammonium bromide; alkanolamide of a fatty acid and 0.25% by weight of ethanolamines, and 0.25% by weight of octadecylamine in the form of 1% emulsion.

The corrosion coupon was of steel grade 12 and did not show corrosion attack after half-year exposure at 3 ° C when it was partially immersed in water.

-3 Industrial use

The corrosion inhibitor for the extraction, transport and storage of natural gas is used in the extraction of acidic natural gas and can be injected into the borehole together with the acid in the so-called intensification of extraction, furthermore as a corrosion inhibitor in underground gas storage environments. corrosion inhibitor in natural gas transport.

Claims (3)

Patent claims Corrosion inhibitor for natural gas extraction, transport and storage, characterized in that it comprises 45 to 55% by weight of a composition. % propargyl alcohol, 23 to Φ wt. dimethylbenzyllaurylammonium bromide, 20 to 26 wt.% triethanolamine phosphate and 0.5 to 1.0 wt. fatty acid alkanolamide. 2. The inhibitor of claim 1 further comprising 0.2 to 0.5 wt. ethanolamines. 3. The inhibitor of claim 1 further comprising 0.2 to 0.5 wt. octadecylamine in the form of a 10% emulsion.