An Innovative Set of Tools for a Sustainable and Safe Offshore Pipelaying

Abstract

Abstract Offshore pipelay is a complex activity that is subject to some risks due to the challenging operating scenario. The risks may concern the workers during pipes handling, the subsea environment that may be subject to huge seabed rectification works and the integrity of the pipeline. This paper will present the technological roadmap developed by Saipem to implement a more sustainable pipelay operation, focusing on the safety and integrity of the environment, personnel and pipeline. Four innovative tools will be described. The Hands Free Lifting Beam (HFLB) is a system for automatic offshore lifting of pipes, removing human intervention and keeping the workers away from the line of fire. The AFT (Anti Flooding Tool) is a remotely operated tool for pipeline protection from flooding in case of a wet buckle occurrence during lay. The I.A.U (Integrated Acoustic Unit) can perform a safe and non-intrusive, continuous piggability monitoring of the pipeline catenary during lay. The UCB (Underwater Cold Bending) is a solution for crossing sharp slope transition avoiding seabed preparation work and associated environmental impacts. The HFLB grabs and lifts the pipes from cargo barge to pipelay vessel under the control of the operator located in a safe area. The AFT runs inside the laid pipeline during the entire lay, remaining in the safe section already laid (free from possible buckling running effects); it automatically plugs the pipe in case of an accidental flooding event, keeping safe the portion of the pipeline already laid. The I.A.U exploits the acoustic reflectometry and can be integrated with the ILUC (Internal Line Up Clamp) on firing line. It is an alternative to Mechanical Buckle Detector (MBD) which is an intrusive system with associated risks for the pipeline like wire break and loss of the device inside the pipeline, device stacking and possible damage of internal coating during pulling. The UCB is a combination of a new installation method and new subsea bending machine ROV operated, to realize cold bends safely and effectively on the pipeline profile without interrupting the continuous pipelay operation. The UCB can realize the bends underwater, directly on the pipeline catenary when the pipe joint to be bent is landing or close to landing on the seabed, reducing the operational cost while increasing the sustainability. The presented tools can pave the way for safer worker operations during pipe handling (with HFLB); for de-risking the flooding of laid pipeline in case of wet buckle event avoiding the use of a dewatering spread and chemicals for seawater treating, reducing costs and environmental impact (with AFT); for de-risking the monitoring of pipeline during lay (with I.A.U) and for a sustainable crossing of steep escarpment without excavation works (with UCB).