Stored Energy in Pipelines

There were repeated incidents on multiple pipeline projects prompted a group of HSE Professionals and Piping Engineers to come together and shared a subject regarding Stored Energy in Pipelines that happened to one of the oil majors few years ago as a lesson learned.

As shown in below figure, the incident was to perform a cold cutting operation to the existing 24” pipeline and more than 11 cuts were safely performed during the project’s execution. The pipe fitter was cutting the 24" pipeline on the dune point as shown. After ending cutting operation using the cold cutting procedure, the pipe suddenly moved vertically about 12" due to the stored residual forces/stresses in the pipe. This movement resulted in hitting the man and tripping him down on the ground.

Potential Outcome: The person(s) doing this cutting job may have been seriously or fatally injured if he was in contact with the pipe.

Likely Causes:

• Unexpected stored residual forces / stresses in the pipe.
• Inadequate risk assessment.
• Lack of proper support over the pipe-work.

Recommendation from the incident:

• Job Safety Analysis should consider alternate cutting positions.
• Pipeline energy storage should be evaluated prior to cutting.
• Provide additional methods of supporting and bracing the pipeline.
• What-if strategy!