For flowlines and pipelines carrying corrosive fluids containing high CO2 and often in combination with high partial pressure H2S corrosion resistant alloys (CRA) are specified.
Corrosion resistant alloy clad and lined steel has been available in various forms for over 50 years  and is widely applied in the oil and gas production industries with generally good experience.
Mechanically bonded lined steel pipelines are considered technically viable and cost effective for field developments with sour service. In these pipelines, a 3mm layer of Corrosion Resistant Alloy (CRA) layer is used typically to form the internal lining. Recent developments, including DNV JIP on Lined and Clad Pipelines, considered for lined pipes the CRA layer is utilised only for pressure containment calculations.
High Temperature and High Pressure (HT/HP) wells pose challenges associated with thermal gradients that may cause pipeline lateral or upheaval buckling. At the buckle crown areas, high strain may develop and due to frequent changes in the operational conditions large cyclic strain may be imposed on the pipe and girth welds resulting from so-called pipeline walking.
Hence, for the mentioned conditions the strain capacity of the girth welds becomes very important and limits the choice of welding processes and consumables as well as imposes tight requirements to the detection capability and sizing performance of the AUT systems.
Although the experience with application of clad and lined pipelines in general is good, DNV GL has experienced a number of projects where clad pipe has failed after short time following installation and in a few cases after longer periods of operation. In the present lessons learnt from the failure after installation and short service of CRA clad and lined pipe are presented. Some challenges in selection of linepipe materials and welding consumables are discussed.
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