Offshore phase separator design & control

[Radionise]

Generally, two questions here:

(1)
Are there any more specific differences in designing a production separator for topside facility compared to those separators for the downstream activities?

(2)
How different is the control system implemented for upstream production separator compared to those separators at downstream (i.e. refinary)? Especially in terms of copping with the occurence of slug flow and fluctuations?

PhD - Permanent Head Damage

 

[JLSeagull]

The control systems onshore could benefit from following the offshore standards. Offshore in the USA the instrumentation and controls must comply with API RP 14C, ANALYSIS, DESIGN, INSTALLATION, AND TESTING OF BASIC SURFACE SAFTEY SYSTEMS FOR OFFSHORE PRODUCTION PLATFORMS.

Independently of the regulatory measurement and controls, a high level trips the inlet. A low level trips the outlet pumps. In addition to the PSV there are high and low pressure trips and perhaps a temperature trip. The check valves have instrument tag numbers, ...

You will likely provide a Safety Instrumented System per ISA 84. A SAFE chart shows the causes, effects and the Safety Analysis Checklist item number. Lots more.

 

[DrillerNic]

The main differences that may affect the design of the actual separator is that space is often at a premium offshore, so some design compromises may have to be made: vertical separators etc (although having said that, in my experience, I've not seen a vertical spearator offshore!). the other affect on floating hosts (FPSOs, TLPs Spars etc) is that the separator is moving: heave pitch and so on, so the internals may have to be modified slightly to allow for this.