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Long Range UT v Intelligent Pigging

Long Range UT v Intelligent Pigging

Long Range UT v Intelligent Pigging

We have a leak on a Riser line that is held inside a J-Tube on one of our installations (pipe in pipe).  The internal pipe is the one that has leaked.

The question is would long range Ultrasonics be capable of picking up a pin hole leak, ie 3mm diameter hole being the worst case.  The defect could potentially be located up to 15m from where the system will be mounted to the riser.

The other option open to us is to use an intelligent pig with a 3mm axial resolution with 64 probes mounted radially.

Any coments/suggestions experiences would be welcomed.


RE: Long Range UT v Intelligent Pigging

Check with one of the acoustic emissions companies they may be able to help you.  Physical Acoustics is one that comes to mind.  

RE: Long Range UT v Intelligent Pigging

Ref Guided Wave/long range UT vs intelligent pigging.
Not sure if you still require this information? Many factors effect the resolution of the Guided Wave such as wall thickness, coating, diameter, features (brackets, vents etc..) if you could supply more infomration I may be able to assist further. We have been involved in Long Range UT for about 5 years and have experience on various different types of inspection.

RE: Long Range UT v Intelligent Pigging

What will be the repair method for the leak?  Surely, that should guide you as to the accuracy of the technique for locating the leak zone.  For example, if the repair proposal is to fill the annulus with some material then there would be no need to locate the leak at all.  On the other hand, if you have a leak, you would, perhaps, want to quantify the extent of metal loss (assuming corrosion) both in the riser and pipeline - that really leaves you having to run an IP.


Steve Jones
Materials & Corrosion Engineer

RE: Long Range UT v Intelligent Pigging

I’m not sure what the accessibility is to the component in question, or what the process media is but here are a few things that come to mind. If your thinking of using a smart pig then I assume putting water in this tube is ok. This may sound odd, but I just thought of it. If you have access to a steam supply you could introduce steam to the inner tube then inspect the outer tube with infrared thermography to pin point the leak area. If you are not dealing with thick tube material the heat should transfer pretty good assuming there is not a lot of air space from the o.d. of the inner tube to the i.d. of the outer tube. If this is successful you could take some profile radiography of the area to obtain an image.  

RE: Long Range UT v Intelligent Pigging


Thanks for the additional info, the intelligent pig located the leak before we had a chance to deploy the long range UT.  


RE: Long Range UT v Intelligent Pigging


My company has recently been using some very sensitive thermal imagery equipment which is hand held for offshore riser inpection in the gulf of mexico.

In your particular situation,
If the fluid in the inner line is at an elevated temperature and under pressure and is leaking at pressure onto the outer, you will probably be able to pin point the leak using this equipment.

If access to the riser is a problem, you could consider using a team of rope access inspectors to perform the job.
We at oceanteam/Diavaz, Mexico could provide this service for you.

fell free to contact me:

K Madden
Tech Support Eng

RE: Long Range UT v Intelligent Pigging

If you check RTD website we have Pipeline inpection tool we can check online (pig goes in and we look real live on the screen if there are any feature)we a have lots of exeprience with riser inspection. and its no problem to detect/find this 3mm feature


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