Fluid mechanics

[Mahmoud Khalaf]

Is it safe and reliable operation to mix 3-phase production stream gathered from a certain offshore oil platform and planned to be connected down stram a pump that discharges liquid stream (oil and formation water)to an onshore separtor? Keeping in mind that pump discharge pressure is greater than the dilvered 3-phase pipeline pressure.

 

[1503-44]

It can be made safe, but whenever the pump is running, it may not be possible for the 3phase stream to enter the connection into the pipeline to the separator, due to a higher pressure from the pump. You have to know the minimum and maximum pressure range of the separator pipeline at the connection point, pump running and pump off.
You may only get flow from the 3phase system when the pump is not running, or maybe not even then. The 3phase will only deliver through the connection to the separator when it can make a higher pressure than what exists at the connecting point.

I am assuming making it safe requires at least a oneway check valve from the 3phase, so no backflow from the pump goes into the 3phase system. That check valve will not open whenever the separator pipeline pressure is higher than the 3phase system, so 3phase flow will stop in that condition. An automatic shutoff valve, relief valve and a backup manual block valve might also be needed on the 3phase pipeline to guarantee that high pressure never can enter the 3phase system, should the check valve fail.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."