Nord Stream pig completes internal trunkline inspection

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

A 7m long and 7 t measurement tool 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. During the 10 day journey, the pig collected over one terabyte of data, and the data was recorded at a rate equivalent to 12 Mbit/sec.

This was the first time that a pipeline of this length and wall-thickness has been analysed in this way. ROSEN Group developed a device with one of the strongest magnetic fields for the inspection run.

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.

Photos and video footage relating to the intelligent PIG and completion of the inline inspection:

• http://www.nord-stream.com/press-info/images/?q=&category=114&per_page=12&year=all
• http:www.nord-stream.com/press-info/footage-videos/?q=&language=all&year=all&category=114&per_page=12

Edited from various sources by Hannah Priestley-Eaton

Read the article online at: https://www.worldpipelines.com/business-news/07102013/nord_stream_pig_completes_internal_trunkline_inspection/