Digital Radiography Inspection of Flexible Risers in Offshore Oil and Gas Industry

This paper presents the development of a digital radiography-based system for sub-sea applications that is being implemented within the context of a H2020 EU funded project called "RiserSure". The system is capable of performing semi-automatic in-situ integrity inspections and providing detailed information on any damage to the metallic layers of flexible risers, without the need to remove the coating layer. The integrated system comprises a subsea digital radiography linear detector array coupled to a commercially available marinised gamma ray source, and a bespoke developed versatile scanning system for deploying the radiography units under subsea conditions for performing precise all-round scanning of risers. Preliminary site shallow sea trials of the prototype system were conducted at the Underwater Centre facilities in Fort William, Scotland. The results, discussed in this paper, validated the effective underwater application and performance capabilities of the system in controlled shallow sea operating conditions, and show the potential for offering reliable and highly accurate radiographic inspection of risers. Finally, from the site trials, the requirements for further system improvements were identified for real-world deployment