dehydrating natural gas 1

[eng9901375]

Why is it essential to dehydrate gas before it is compressed and exported from the platform?

Also, what special considerations must be given to the design and operation of the gas export pipeline if the gas contains substantial amounts of carbon dioxide?

 

[Nosey]

There are several reasons for dehydrating gas before compressing and exporting it

1/ Reduce corrosion in the export lines as a result of condensation of water in the pipelines.
2/ Prevention of hydrate formation as the gas cools down in the export pipeline.
3/ Reduction in the formation of a liquid phase in the pipeline and therefore a reduction in the possibility of slugging (depends upon a lot of other factors as well i.e. flowrate, length and diameter of pipeline, total cooling etc.)
4/ Reduce the corrosion experienced by the export compressor by passing warm, wet gas into it.

As for handling significant percentages of CO2, I would expect that corrosion issues would be foremost in your mind so you would have to be very careful with your materials selection for the pipeline. I assume that the plant you are exporting this gas to will be able to cope with a high CO2 concentration.

I hope that this is of use to you.

For further information refer to Gas Conditioning and Processing Volume 2 by JM Campbell & Co. (currently in it's 8th Edition)

 

[Nosey]

This is the same as

thread469-54444