Non-Destructive Testing of pipeline welds with a CRA layer

摘要

An increasing number of offshore pipelines is built using a corrosion resistant allow (CRA) layer. Due to specifics of the welding procedure, the method of bonding of the clad layer, and the metallurgy of the resulting weld, this creates challenges for Non-Destructive Testing (NDT). These challenges become critical to the pipelines fitness in cases where acceptance criteria are stringent, such as fatigue exposed pipelines and pipelines with a strain based design. Over the last ten years, Applus RTD has built a suite of technologies for dealing with these issues.The paper gives an overview of the features of CRA layers relevant for NDT and will present the direction for testing that has been developed at Applus RTD. Both automated ultrasonic testing and digital radiography options will be treated, tracking improvements over the year. Examples of field testing and qualification testing will be presented from developments like Shell Bonga and Encana Deep Panuke. Finally solutions currently in development will be disclosed, presenting NDT3D as implemented in RTD Rayscan 3D and RTD IWEX 3D.