The Challenge

Image The Challenge

Operators have to contend with many obstacles in order to obtain high resolution data for their pipelines.  The inspection of gas storage laterals are no exception. Though they vary in complexity with each pipeline containing its own unique characteristics, the following obstacles were consistent in each storage lateral presented in this challenge:

  • No launchers and no receivers
  • Only one location where access could be provided
  • 10” lines connect to 20” trunk line
  • Limited flow conditions available


Image Solution

After all alternative solutions were evaluated, it was determined that a bi-directional MFL based crawler solution best suited the challenges present in these pipelines.

Within 5 months ROSEN designed, manufactured, assembled and tested the new Multi-Trotter Crawler (MTC) inspection system.   With the self-propelled Multi-Trotter Crawler providing the driving force for the inspection system,  a compact bi-directional low friction MFL unit provided the inspection data.  The exceptionally powerful crawler unit ensures greater passage capabilities and the flexibility to safely negotiate various obstacles all while towing a high resolution magnetizer unit.

As with all solutions a well-designed fail safe system is essential, what goes in the pipeline must come out. For this application ROSEN’s engineers utilized a collapsing ”gripper” failsafe and a tethering retrieval unit. In addition, this solution contained innovative elements such as:

  • High resolution MFL technology – no compromise to data quality
  • Bi-directional / low friction magnetizers 
  • Onboard power storage
  • Visual monitoring
  • Power consumption monitoring
  • Sensor detection of tee’s


Image Benefit

Extremely powerful crawler provides full control over the tool movement while designed fail safe measures ensure the tool can always be recovered. This ensures safety regulations are continually met.


High resolution MFL data quality, 100% coverage in one single pass, meeting strict regulatory requirements. Additionally tool records in both directions.


MFL technology is a robust and proven technology known to be least sensitive to debris. Increasing first run success rate and reducing miscalls.


Bi-directional approach avoids the need for costly pipe modifications for launching/receiving while MFL technology does not require a liquid medium.


The crawler approach avoids the need for costly heavy equipment such as compressors/wire line trucks.