Steam Injection Line MI Thermocouple Failure

[MATe10]

Hello All,

I have a 1/8" diameter 316 SS sheathed magnesium oxide insulted thermocouple that was placed inside a steam injection well for a SAGD operation that has failed.


It was subject to ~240C temps and 1400kPa pressures and also inadvertently exposed to around 10ppm chlorides and 51 ppm H2S.

The MI thermocouple sheathing is 0.017" thick and has appeared to rupture from the inside out, at several random locations in the first 15 m of the well.

Any thoughts as to the cause of this would be appreciated. Thank you

 

[StoneCold]

My first thought is why is your thermocouple not isolated in a well. As to why it opened up on you I have no idea.
What is a SAGD operation?
Regards
StoneCold

 

[MATe10]

It was enclosed in another 316SS capillary tube, however it appears to have been breached and some of the reservoir fluid and steam entered. SAGD(Steam Assisted Gravity Drainage) is a method of obtaining bitumen from oil sands by injecting steam into a well and collecting the heating bitumen.

 

[EdStainless]

Move to a Ni alloy for sheathing. Sounds like SCC failure to me.
If you look carefully there should be thousands of very small cracks near the major ones.


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Plymouth Tube

 

[metengr]

Send it out for a proper failure analysis at a met lab. Don't guess.