Unbonded flexible pipe integrity management, reuse and life extension
Adriana Botto A , Céline Banti A and Enda O’Sullivan AMCS
The APPEA Journal 48(1) 319-328 https://doi.org/10.1071/AJ07021
Published: 2008
Abstract
Australia has a long tradition of innovation in the use of floating production systems in the past 20 years. The classical solution adopts unbonded flexible pipe, a key technology, to enable floating facilities to produce in relatively shallow waters. While unbonded flexible pipe is a reliable technology that has been in use for approximately 30 years, damage, and ultimately failure can occur during its early (i.e. during manufacturing/testing, installation and early operation) and later life.
Accurate assessments of the historical records of flexible pipe usage have led to an increased understanding of the potential failure mechanisms. This enables mitigation of incidents by developing operating strategies and procedures to manage the flexible pipe in a knowledgeable and cost effective manner.
This paper discusses the available techniques for the inspecting and monitoring requirements of flexible pipe, including consideration of the value offered by conventional general visual inspection (GVI) techniques. Examples of developed alternative technologies are discussed, as well as how these alternatives can reduce the requirement for GVI when supplemented with an integrated integrity management strategy.
Furthermore, given the advances in understanding of complex flexible pipe inter-layer behaviour, this paper demonstrates that through proper asset management, flexible pipe technology service life can be extended beyond the original design value. Similarly, flexible pipe that had previously been considered damaged and requiring early replacement can be justified for extension to beyond the original design life.
Consideration has also been given to the potential for the re-use of flexible pipes and the hazards which can arise from this activity including recovery, storage, testing and installation. The key stages required to safely manage this process have been outlined.
Adriana Botto is the integrity management team leader at MCS, Perth. She has recently completed the Stybarrow BHP Subsea Equipment Integrity Management Plan and is developing the Integrity Management Strategies for Woodside flexible pipes. Adriana has over five years experience with Petrobras where she was a member of the integrity management group in the inspection and maintenance department, with a focus on the structural integrity of flexible pipe. She played an integral role in the development of the risk-based inspection program and was responsible for the flexible pipeline inspection program on the Marlim field. Adriana has a Masters degree in Ocean Engineering from COPPE/Federal University of Rio de Janeiro. Her research included the integrity assessment of reel lay SCRs as well as external corrosion effects on pressure capacity of pipelines. In addition, she has published numerous papers at leading offshore conferences, such as OMAE, IPC and IMAM. AdrianaBotto@mcs.com |
Céline Banti has over two years experience in the design and integrity management of flexible pipes. She has recently performed the integrity management assessment for the Ichthys Field (Inpex), which encompassed risk assessment, an integrity management plan and specification of the condition monitoring equipment. She also has been involved in different integrity management projects for Woodside, and the Stag and East Spar fields from Apache. She has worked on failure investigation and reliability studies of flexible pipes. She has a Masters degree in Ocean Engineering from ISITV/Engineering School of Toulon, France. CelineBanti@mcs.com |
Enda O’Sullivan is operations director at MCS, Perth, and a chartered engineer with over 16 years experience in offshore engineering. Enda was recruited by MCS as a graduate to work in the software department. He then moved on to project work in Aberdeen and rose to the role of General Manager, relocating to Houston as VP for business development. He is a fellow of the Society of Underwater Technology. His technical expertise primarily covers design and integrity management of risers and he actively consults on projects, mostly for southeast Asian floating and subsea projects. Enda is active in the industry, presenting at and chairing sessions for offshore related conferences. He has recently presented papers at Offshore Asia (OA), Deep Offshore Technology (DOT), Offshore Technology Conference (OTC) and OMAE. He chairs the annual session Advances in Riser Technology at OTC. EndaOSullivan@mcs.com |
