Deployment of digital radiography for subsea inspection of flexible risers
A L Clarke, G Liaptsis, S Hall, C Forrest, P I Nicholson, A Kaur, B Ma and M Corsar
TWI, in conjunction with the RiserSure consortium, has developed an underwater digital radiography system for inspection of underwater flexible risers. Water is highly attenuating and, in order to acquire underwater radiographic images, radiation energies used must be higher than for in-air applications and the radiation path between radiography source to detector must be minimised. This presents challenges for deployment of a practical inspection solution.
The RiserSure developed system utilises the novel concept of a subsea deployable digital radiography (DR) linear detector array coupled with a commercially available underwater gamma radiation source deployed by a custom developed marinised robotic scanning system. The DR linear detector array, compared to a flat panel DR detector solution, offers greater sea depth potential in a smaller package and the ability to cope with the higher radiation energy available from an Ir192 gamma source. The development work, project final year findings, including sea trial results, and future application are presented. Much development has gone into improving the TRL of the original laboratory system in to a field-deployable commercial-ready solution. The trial results have validated the effective underwater application and performance capabilities of the system in sea operating conditions and prove the potential for offering practical deployment of a reliable and highly accurate radiographic inspection system for flexible risers.
The RiserSure developed system utilises the novel concept of a subsea deployable digital radiography (DR) linear detector array coupled with a commercially available underwater gamma radiation source deployed by a custom developed marinised robotic scanning system. The DR linear detector array, compared to a flat panel DR detector solution, offers greater sea depth potential in a smaller package and the ability to cope with the higher radiation energy available from an Ir192 gamma source. The development work, project final year findings, including sea trial results, and future application are presented. Much development has gone into improving the TRL of the original laboratory system in to a field-deployable commercial-ready solution. The trial results have validated the effective underwater application and performance capabilities of the system in sea operating conditions and prove the potential for offering practical deployment of a reliable and highly accurate radiographic inspection system for flexible risers.
