Image Challenge

An operator’s  need for  comprehensive inspection solutions is no longer limited to just pipelines. Such is the case for gas storage tubes and though while similar in nature to “normal” pipelines, underground gas storage tubes contain mainly elements which prevent operators from utilizing conventional ILI  methodologies for their inspections.

Though pipelines with similar diameters do not necessarily pose an issue for standard tools and technologies, storage tubes bring their own obstacles:

  • Access not sufficient for ILI tools
  • No flow for ILI tools
  • Single access only


Image Solution

Individually, the obstacles presented in the storage tubes may have been resolved with a more standard ILI solution, it was the combination which demanded a new approach. In 11 months ROSEN was onsite with their newly designed, manufactured, assembled and tested RoHelix MFL inspection service. 

With the self-propelled axial movement technology as the primary drive for the tool, an MFL supported helical measurement technology provided the inspection data.

As with all solutions a well-designed fail safe system was essential, what goes in the pipeline must come out. To meet safety requirements ROSEN’s engineers utilized a tethering retrieval unit and cable assisted retractable yokes. In addition, this solution contained innovative elements such as:

  • High resolution MFL technology
  • Bi-directional / low friction yokes 
  • Onboard power supply
  • Visual monitoring
  • Power consumption monitoring
  • 48”-54” diameter range


Image Benefit


Full coverage maximizes data potential reducing unnecessary digs and downtime due to miscalls. 


Proven MFL-based corrosion inspection meets strict regulatory requirements.


Design minimizes onsite equipment requirements.

Cost effective   
No traps required - minimal requirement for auxiliary services and modifications.


Tool design covers 48”-54” reducing need for multiple tool design costs and specialized support equipment.


Controlled, bi-directional operation including fail safe mechanisms, ensuring the highest in safety standards.