Gas detection on Flowlines - Pin Hole leaks


Thread Starter


During the meeting late last week, it was asked if there is a possibility to site some gas detectors (or something) near the more critical of the welds to allow detection by something other than the Operators’ nose.

Can you please take a very cursory look at that possibility/feasibility without significant modifications? Let’s start with just 5-10 detectors near our most critical welds near the wellheads and the chokes.

There is also recommendation:
1.Pin hole leaks can not be reliably detected using line of sight or conventional point type gas detectors because the released gas will rapidly disperse below detectable levels.

2. Either multiple detectors would be required around each weld or we would need some form of collection hood placed around the weld and have a gas detector draw a sample from the hood.

3. Unless carefully considered, the detectors or hood may actually inhibit the ability to easily conduct a visual inspection.

4. I suggest that ultrasonic leak detection maybe the most suitable technology to use for small leaks. Perhaps it is worth looking at the Emerson GDU model ultrasonic detector. I think it is likely to give better coverage than point or path type detectors. The advantage of ultrasonic technology is that it does not physically need to come in contact with the hydrocarbon. It only has to “hear” the sound of a leak. However coverage would be limited to maybe only 2m radius around each detector if we are trying to hear small leaks. The disadvantage is they are more expensive and most likely more suited to detecting a leak of high pressure gas

Could you please share your experience in this kind installations?