Prism Energy Oversee Successful North Sea Pigging Operation

Throughout 2022, Prism Energy took charge of a major North Sea pipeline cleaning campaign and in-line inspection tool run. The pipeline system is operated by a third-party operator with multiple entrants leading to a scope with many complex timing interfaces.

The initial campaign involved the launch of multiple cleaning pigs to ensure that the line was in a suitable condition for an inline inspection tool.


To ensure the efficient cleaning of the pipeline, a debris mapping tool was deployed at the beginning of the project, this returned accurate data detailing the quantity and location of deposits within the pipeline. This data was then analysed to select appropriate cleaning pigs for the operation.

Nine cleaning pigs were then launched in total. All nine cleaning pigs were recovered successfully along with the debris from the pipeline. Thereafter, the in-line inspection tool was launched and recovered successfully, marking the end of a successful pigging operation. 

The data gathered from the in-line inspection tool is now being analysed by the in-line inspection tool vendor, before issuing a report to all entrants.


The successful cleaning campaign was arduous and wasn’t without its challenges, the team navigated multiple obstacles and risks including three wye shaped junctions in the pipeline, 3D & 5D bends, an unmanned receipt platform operated by the pipeline operator, and pitstops/shutdowns throughout the summer months. Further hurdles involved unplanned shutdowns and a vendor going into administration. These challenges were negotiated and overcome/mitigated allowing the team to reach the milestones of the in-line inspection tool launch.

Longer-Term Benefits

The success of the project has allowed the operators to streamline their standard cleaning pig programme. Previously the pipeline cleaning schedule was based on a six-week reoccurring cleaning operation. However, thanks to the introduction of more efficient cleaning pigs (used on this project), going forward the intention is to continue using the more efficient pigs on a 10-weekly basis, maintaining cleaning efficiency, but reducing the operational impact.