A insuled hydrocarbon pipeline at a hydrocarbon extraction and shipping depot was found to be leaking at the point where the pipeline enters the ground. At around 6:30 p.m., a private individual discovered the spill and notified the depot ‘s security officer. The leak was located and isolated. A sand barrier was set up around the spill. The depot’s production and shipment operations were halted.

An estimated 600 l of crude oil spilt over a 30-m² area. The next day, a specialized firm excavated 2 m³ of contaminated sand. It was stored in a leaktight skip pending its transfer to an approved treatment facility. The pipe was repaired by cutting off and replacing the damaged section. Production and shipments at the depot resumed at around 2:30 p.m.

Initial findings revealed corrosion on a lagged section of the pipeline. 

The causal analysis showed that:

• the lagging was faulty where it met a lightning protection connector;
• the section had a painting default.

No corrosion had been found in this section when intelligent pigging was last performed in 2012 (the next such inspection was scheduled for 2018). A visual inspection involving removal of the lagging had been conducted in 2001 but did not include the pierced section. In-service monitoring of the pipeline therefore did not detect anything preventively.

The operator:

• had the lagging removed from the rest of the pipeline (other areas of significant corrosion were identified);
• replaced the corroded sections by a new painted pipe surrounded by suitable lagging that allows access to critical points;
• fitted a valve for isolating the pigging station in case of a problem.

Finally, a national action plan was then drawn up to:

• identify and visually inspect lagging at various sites;
• remove lagging from sections at risk of water intrusion (nozzles, valves, ascending elbows, etc.) and extend lagging removal where necessary;
• occasionally carry out non-destructive testing on sections from which lagging was removed;
• check the need for lagging and permanently remove lagging from sections that do not need it.

Lastly, the inspection authorities for classified facilities asked the operator to update and supplement the pipeline’s monitoring and maintenance plan.