Processing method for butt welding of small-caliber inner corrosion resistant pipeline

Abstract

The invention discloses a processing method for butt welding of a small-caliber inner corrosion resistant pipeline. The method comprises the steps that upsetting treatment is firstly conducted on theend of a tube blank, and then burn through is conducted; bead weld groove processing is conducted on the inner wall of the end of the pipeline, the starting point of the groove is a corresponding position from an external thickening starting point, and the depth of a groove is conformed to the external thickening amplitude; the arc starting point is at the groove starting point, and a bead weld layer completely fills the groove; inner corrosion resistant treatment is conducted on the pipeline, and the pipeline is coated with a corrosion resistant layer; the corrosion resistant layer is an organic coating or a corrosion resistant alloy coating; finally butt welding is conducted on the pipeline. The method has the advantages that the integral strength of the pipeline is not influenced when bead weld groove is processed through an end external thickening manner, smooth transition of the inner wall of the pipeline is ensured after bead weld is completed; the damage on the corrosion resistant layer by high temperature is effectively avoided in the welding process, and the continuity of the inner surface corrosion resistant layer of the pipeline is achieved.

Description

Technical field [0001] The invention relates to the field of pipelines, and more particularly, to a welding connection method for a small-caliber internal anticorrosive pipeline. Background technique [0002] In the production process of oil and gas fields, the pipeline has been exposed to high temperature, high pressure, CO 2 / H 2 S, containing Cl - In the environment of formation water, corrosion problems are very prominent, and traditional carbon steel pipelines will also face more and more severe tests. Although the corrosion-resistant alloy can effectively solve the corrosion problem, its cost is relatively high, and the one-time investment amount is relatively large. The coating technology on the inner surface of the pipeline is a very economical and effective anti-corrosion measure. However, the oil and gas surface pipelines are all connected by welding. In order to ensure the continuity and integrity of the internal coating of the pipeline, the weld joints need to be coa...

AI Technical Summary

Problems solved by technology

[0003] In view of the above problems, the purpose of the present invention is to propose a welding joint for small-diameter internal anti-corrosion pipelines, which overcomes the problem that the existing small-diameter internal anti-corrosion pipelines are difficult to repair after welding, and makes the corrosion resistance of pipeline butt welded joints reach even Exceeds the internal coating pipeline, and realizes the continuity of the anti-corrosion layer on the inner surface of the pipeline

Images