Record breaking pig run for inspection of Nord Stream pipelines

Nord Stream has concluded a comprehensive inspection of the internal condition of both the Nord Stream pipelines, as part of its long-term safety and pipeline integrity management strategy.

A measurement tool about 7 m long and weighing more than 7 t was sent through the pipeline from Russia to Lubmin, Germany, travelling at 1.5 m/sec, propelled by the gas pressure. The pipeline inspection gauge (pig) collected high-resolution data on material integrity along the 1224 km route. The journey for Russia to Germany took 10 days.

A first for inspection tools

This was the first time that a pipeline of this length and a wall-thickness of up to 41 mm has been analysed in this way.

For the inspection run, a device with one of the strongest magnetic fields was developed by ROSEN Group in Lingen, Germany.

Pig collects one terabyte of data

The intelligent pig has an array of electronic sensors, which screen the material integrity and the geometry of the pipeline. The pig has collected over one terrabyte of data on its journey from Russia, and the data was recorded at a rate equivalent to 12 Mbit/sec, 30 times faster than cellular data networks.

Pipeline conditions

The high-resolution measurement technology can detect the smallest changes in the condition of the pipelines.

The exact geographical position of the pipelines is also being documented. The first evaluation of the results confirms that the pipelines have moved only minimally while being operated under full pressure and that there has been no corrosion or deformation.

External inspection was carried out first

In 2012 and early Summer of 2013, Nord Stream examined the external condition of both pipelines.

This external visual and instrumental inspection of the pipeline was conducted via remotely operated vehicles (ROVs) followed by support vessels. The results of the internal and external inspections form the baseline data for regular inspection cycles in the coming years. This will allow any potential changes in the position of the pipes, minimal corrosion and even the smallest mechanical defects to be detected at an early stage.

Adapted from press release by Elizabeth Corner

Read the article online at: https://www.worldpipelines.com/business-news/30092013/record_breaking_pig_run_for_inspection_of_nord_stream_pipelines/