batching

[pipeeng3000]

Does anyone know the main issues surrounding batching of different types of crude in an onshore pipeline. What additional facilities/ considerations should be made? is it generally feasible in all pipelines. The two types of crude do not differ that much; densities 800 and 850. Are there any good info sources for this subject? thanks

 

[BigInch]

Interface Tanks.
Interface cutting header and valves.
Densitometers, early warning and for final cut.
Check Valves and Double Block & Bleed valves at inlet header.
More power and head for the heavier crude.
Minimize dead legs.
Interface length calculations can be done by Austin-Palfry or similar equations.


If you were plowing a field, which would you rather use? Two strong oxen or 1024 chickens?" - Seymour Cray (1925-1996), father of supercomputing
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http://virtualpipeline.spaces.live.com/

 

[pipeliner3000]

Thanks,

I am not expecting much variation in discharge pressure for the two crudes between 90 - 100barg. Also flow would be fixed. I am ramping up to meet final flow and thinking about using pumps in parallel. Is there a case for series pumps here..?

 

[BigInch]

I wouldn't think so. With such a small variation in discharge pressure needed between the two crudes, it doesn't seem warranted. Series might be needed with hot heavy crudes, where the viscosity changes by a factor of 10 between ambient temperature and flow temperature. Start up after a cool-down period might require series pumping until the whole line gets hot, at which time you could change to parallel pumping. Something like that would make being able to change the configuration really usefull.

"Make everything as simple as possible, but not simpler." - Albert Einstein (1879-1955)
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http://virtualpipeline.spaces.live.com/

 

[jmw]

In some of the Gulf of Mexico ports where multiple crudes may be delivered through a common pipeline they have digital process viscometers installed along the pipeline to "identify" the crude from its known base density and base viscosity.
This identification allows them to dose the crudes with the appropriate amount of "snot" (drag reducer) which optimises the flow rates for the available pump pressure.

Snot is expensive and overdosing doesn't further reduce the pipe friction, it just costs more and apparently there is an optimum amount for each crude.


JMW

http://www.ViscoAnalyser.com