3 replies to this topic

[Highlander]

Hello,

I am trying to find out how can I calculate what is the separation efficiency (volume percent) of the oil or produced water outlets of a separator.

For instance, it is common for a simple gravity 3-phase separators to have a separation efficiency of 5% - 10% water in the oil outlets. While this appears to be based on empirical and experience, I like to know if are there any equations or methoda I can utilize to calculate out a basic estimation of the volume percentage at the outlets.

While using Stokes' law, we can have an estimate on the droplet size of water in oil outlets, but I do not know of any relationship in which I can find out what is the volume percentage of water in oil outlets.

Any advice or help rendered to clearing up this confusion is greatly appreciated.

Thank you very much.

[paulhorth]

Highlander,

I think what you are looking for is a Droplet Size Distribution - that is, a curve of volume percent versus droplet size for the water. This data is not readily available, except possibly within the specialist equipment vendors. It is also difficult to measure. The size distribution of water droplets depends on what is happening upstream of the separator - whether the fluid has been through a valve with a large pressure drop ( usually the case), or a pump, or a heater. It also depends on the emulsion-forming nature of the fluid, which depends on the chemistry of the oil, whether any solids present, etc....

So - even if you could find a droplet size distribution in the literature, it might not be right for your application. The best guide for what you can expect would be actual measurement of water carryover from a separator in similar service, but even then that might not be valid, because the separator could be overloaded, full of solids, etc etc...

The major oil companies provide guidance on typical water carryover in their design standards, but these are not in the public domain.

Paul

[Highlander]

Hello Andrei2011 & Paulhorth,

Thank you very much for your explanation.

Andrei2011 - You have misunderstood my question. But thank you for your response in any case.

Paulhorth - Thank you for your explanation. You have clarified up this issue for me.

Cheers,
Highlander

[andrei2011]

Highlander,

I am sorry if I've wasted your time with my post, I've deleted it.
I guess next time I will try to be wiser and take the stance that somebody like Art is taking in such situations and say: dear Hyghlander your question is not complete and lacks basic information for a right understanding of your question.
Sory for any inconvenience caused.

Good Luck