Hydrate formation in piping bends
Hydrate formation in piping bends
(OP)
I am looking at wet natural gas piping system.
An expert has advised that hydrate crystals have a tendency to accumulate at piping bends (radius < 3d).
Intuitively, this does not seem right. Also I have been unable to find any references to the phenomenum on the internet.
Has anyone got any knowledge about this?
Regards,
djwright
An expert has advised that hydrate crystals have a tendency to accumulate at piping bends (radius < 3d).
Intuitively, this does not seem right. Also I have been unable to find any references to the phenomenum on the internet.
Has anyone got any knowledge about this?
Regards,
djwright





RE: Hydrate formation in piping bends
Best regards
Morten
RE: Hydrate formation in piping bends
I have a lot of experience with hydrates, most occuring around 4 am in a cold windy place. Early models predicted hydrate formation based on bulk fluid temperature. This proved to be incorrect. It is the pipe wall temperature that drives the formation of crystals. Most references will state free water has to be present. THIS IS INCORRECT. The temperature of the pipe wall has to be below the water condensation temperature and the temperature of hydrate formation. Pipe bends seem to be a good place for these crystals to accumulate.
An excellent reference source is Dendy Sloan's book "clanthrate Hydrates". I can help with resolution of your hydrate problems. 713-204-3615.
RE: Hydrate formation in piping bends
I have not read the book that you reference (but i have started pestering my manager to buy it for me
Best regards
Morten
RE: Hydrate formation in piping bends
My original post was I think slighly misleading. A reinterpretation of the expert's view is that turbulent flow regimes can promote hydrate growth.
Typically, a production well has xmas tree, pipework with choke, NRV connected to a manifold by means of a tee.
Our flow stream is susceptible to hydrate formation during start-up and designers have now suggested we can minimuse turbulent flow and reduce the risk of hydrate formation by eliminating the NRV and replacing the conventional tee with a swept tee.
Sounds sensible?
Regards,
djwright