Pressure drop accross the wellhead choke 1

[Buchi]

Hi guys,

can someone help me with any rule of thumb on the allowable pressure drop across a wellhead choke. I know that an excessive pressure drop across the choke can give rise to operational issues like hydrate formation and stuff, can there be an allowable pressure drop number like percentage of the Flowing wellhead tubing pressure to avoid the above problems?

thanks,

Buchi

Buchi

 

[TD2K]

There are some allowable pressure expansion curves in the GPSA Engineering data book to avoid hydrates. I suggest you get a copy of them. The allowable expansion is a function of the starting pressure and temperature and gas SG.

 

[BSMP]

If you have access to any simulator like HYSYS, you can verify the hydrate point. To avoid start-up hydrates across the chokes, it is usual practice to dose hydrate inhibitor upstream of the choke.