The Research and Application of ECA Technology for Large Diameter Thick Wall Subsea Pipeline in a Gas Field in Deep Water of South China Sea

In order to ensure the integrity of subsea pipeline in the whole design life, it is very important to carry out quality evaluation for the girth welding since severe ocean environment and installation conditions. In this paper, based on the principle of “suitable for use”, the level 2B, British BS7910 standard fracture assessment criterion is adopted. According to the mechanical properties of the pipe joint, welding method and installation load conditions, the Engineering Critical Assessment (ECA) has been carried out for an export subsea pipeline in a gas field in deep water of South China Sea. Larger allowable initial weld flaws can be accepted through ECA evaluation, the acceptable criterion for AUT inspection in the process of pipeline laying is obtained, which effectively reduce the welding repair rate with significant cost saving and improve installation efficiency.