Preservation of coated pipes

摘要

Dr. Shiwei William Guan, Bredero Shaw - a ShawCor Company, Canada, discusses the mitigation of pipe end coating disbondment due to long-ten storage. As more and more new oil and gas reserves are developed in more challenging and remote locations, increased transportation difficulties and increased long distance pipeline constructions have been seen. Large pipe volumes are often required on a single pipeline project, and thus pipe coating activities may take place several months or even years before the coated pipes are loaded out for installation. Storage of coated pipes for an extended period, especially in the tropical environment, can lead to deterioration of pipe ends and coatings. Moisture and rust weakens the bonding of the anti-corrosion base layer, often being fusion bonded epoxy (FBE), to the steel substrate. Over time, disbondment can occur, particularly at the cutback of thick 3-layer and multi-layer polyolefin coating or insulation systems due to high residual stress.