Subsea Pipeline Integrity Assessment & In-Line Inspection

Client: Regional petroleum products terminal operator
Scope of work: Inspection & Integrity Assessment, In-Line Inspection, Integrity Management
Partnership: Executed using T.D. Williamson intelligent pigging technology
Duration: 5 weeks

Overview
Onflow was contracted to carry out a full integrity assessment of a subsea pipeline connecting an offshore mooring buoy to an onshore petroleum products terminal, following several years of continuous operation without a prior in-line inspection.

What we did

  • Performed pre-commissioning checks and pipeline cleaning runs ahead of the inspection campaign
  • Deployed intelligent pigging tools to conduct a full in-line inspection, identifying wall-thickness loss, corrosion, and geometric anomalies along the subsea and onshore sections
  • Cross-referenced inspection data against an integrity management framework to prioritize findings by risk
  • Delivered a full technical report with repair and monitoring recommendations, in line with international pipeline integrity standards

Result
The inspection identified two localized areas of external corrosion below critical thresholds, allowing the operator to schedule targeted repairs during a planned maintenance window rather than facing an unplanned shutdown. The full subsea and onshore sections were confirmed fit for continued service, extending the asset’s operating life with a clear, risk-based maintenance plan going forward.