Pipeline Operation & Maintenance

The offshore and onshore sections of the pipeline are protected against internal and external corrosion.

In order to prevent internal corrosion, inhibitor chemicals will be continuously injected into the pipeline at the gas well out at sea. The inhibitor chemicals will be pumped out to the gas well via a small pipe (known as an umbilical) linked to the terminal at Bellanaboy.

Protection for the outside of the pipeline will be provided via a 3 layer polypropylene coating as well as a low voltage back up system.

Monitoring tools and techniques will also be used to gather data on the internal and external condition of the pipe and to ensure integrity along its full length. These include pipeline inspection tools that are pushed through the pipeline.

All inspection data will be reviewed by the operator and the regulatory authority.

Methanol Injection

Methanol is added to the gas at the well. It acts as an anti-freeze and prevents the formation of small ice crystals known as Hydrates. The methanol is recovered at the terminal and is re-used back at the gas well - i.e. it is continuously recycled.

Leak Detection—Odorant

Odorant is added to natural gas as an effective means of alerting domestic consumers of leaks in appliances, for instance when a gas cooker in a kitchen does not burn but the gas is still flowing. In the case of Corrib gas, odorant will only be added after the gas has been treated in the terminal as is done elsewhere in the world.

Leak Detection—Pressure Drop

Pressure, temperature and gas flow rates will be monitored on a continuous basis at the gas wells and at the terminal. This allows a calculation to be carried out to account for all gas entering and leaving the pipeline and alerts the operator rapidly about any potential problem.