Design method of long-acting liquid anti-corrosion layer of multiphase conveying pipeline

Abstract

The invention discloses a design method for a long-acting liquid anti-corrosion layer of a multiphase conveying pipeline. The design method comprises the steps of 1, preparing an initial corrosion product on the surface of carbon steel; 2, regulating and controlling wettability of a corrosion product; 3, preparing a carbon steel oil storage surface; 4, evaluating the durability of the oil storage surface in a water flow environment; 5, evaluating the reliability of the oil film under the action of multi-cycle oil-water alternation; 6, achieving dynamic healing and long-acting protection functions of the carbon steel oil storage surface in an oil-water alternating environment; and if the evaluation in the step 4 and the step 5 can be passed, implementing the step 6, otherwise, returning to the step 2 and the step 3, and carrying out a new round of evaluation until the evaluation in the step 4 and the step 5 is passed in sequence. According to the design method disclosed by the invention, the hydrophilic and oleophobic characteristics of a low-carbon steel surface corrosion product are changed, the adhesion capacity of an oil film is improved, the protection time of the oil film is prolonged, and the corrosion inhibition effect of crude oil is enhanced in fluid environments of slug flow, dispersed flow and the like of oil-water mixed transportation and a fluid environment of an oil-water alternate transportation mode.

Description

technical field [0001] The invention relates to the field of corrosion protection in oil and gas fields, in particular to a design method for a long-term liquid anti-corrosion layer of a multi-phase transmission pipeline. Background technique [0002] The transport medium of oil and gas pipelines is generally three-phase or multi-phase fluid of oil, gas and water, the flow pattern is complex and changeable, and the inner wall of the pipeline is always in a state of alternating oil and water wetting, so its corrosion protection is extremely challenging. At present, the technologies applied to corrosion protection of oil and gas pipelines mainly include the following types, namely, corrosion-resistant pipeline materials, inner linings or coatings, and addition of corrosion inhibitors. Corrosion-resistant pipeline materials mainly face problems such as high engineering costs in actual industrial production. For example, the cost of corrosion-resistant alloys such as stainless s...

AI Technical Summary

Problems solved by technology

However, the forced emulsification method is generally only applicable when the comprehensive water content is lower than 30%. The viscosity of the emulsion with too high water content is too high, which will lead to high energy consumption in pipeline transportation; the high gas-liquid ratio corrosion inhibition method is only suitable for CO 2 Oil flooding and other special working conditions with more gas content; the critical flow rate required for high-velocity transportation to form oil-water dispersion flow generally far exceeds the actual production conditions

These practical problems have seriously limited the effective performance of crude oil corrosion inhibition.

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