Challenge
A UKCS operator required quantified condition data for a subsea production pipeline system that had reached the end of its original design life following approximately 15 years of operation. The 30 km loop incorporated flexible steep-wave risers and rigid pipeline infrastructure, creating additional complexity for an inspection pigging campaign.
Existing topsides pigging equipment had also seen limited use since commissioning, while the offshore execution needed to align with a tightly defined shutdown window. A reliable inspection strategy was therefore required to generate the condition data necessary to support future pipeline life-extension decisions.
Solution
THREE60 was engaged to develop the inspection programme and manage the engineering and execution of the pigging campaign using the existing topsides facilities.
With execution aligned to the end of the asset shutdown, the team rapidly progressed contractor selection, engineering and development of the pigging strategy. A risk-based approach was established to address the principal execution challenges, including debris management, pipeline cleaning and safe passage of inspection equipment through the flexible risers.
THREE60 coordinated the engineering and execution interfaces to ensure the system was appropriately prepared and the inspection campaign could be completed within the available operational window.
Result
The inspection pigging campaign was completed safely, without incident and in accordance with the agreed execution plan. Approximately 95% data coverage was achieved across the pipeline system, providing the operator with quantified condition information rather than relying solely on design assumptions.
The resulting dataset provided a robust technical basis for subsequent pipeline life-extension assessment and informed integrity management decisions for the ageing infrastructure.
