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[Jeffs]

In a pipeline simulation (transmission pipeline), from a gas compression plant to a gas processing plant, for the flow assurance simulation using OLGA, why is it that one I am reviewing (Flow Assurance report by other CONTRACTOR), the simulation targets the required pressure at the gas processing plant.

 

So their output indicates calculated required inlet pressure from the gas compression plant, when the gas compression plant has already been designed for a specific rated discharge pressure (from compressor) and even has control mitigations for too much high discharge pressure from the GCP, which will trip the specific compressor. One of the simulated case actually calculated a higher inlet pipeline pressure from the GCP (exceeding trip pressures). So the simulation is backcalculating the inlet pressure of the pipelines from the gas processing plant pressure requirement.

 

So, why is it not set going forward hydraulics (from a set pressure of different GCPs (rated discharge pressure to the maximum required flowrate in the gas processing plant)?

 

I haven't actually used OLGA.

 

I hope my question is clear.

[Pilesar]

Flow simulations often require the user to iterate. Change the required parameter setting until you get the results you want. It usually does not take much time to do this. In general, flow simulators calculate flows using pressure at nodes as the starting point. There are mathematical reasons for this because of the equations relating flow to pressure. When there are gathering systems and distribution systems and both in one network model, sometimes the user cannot even tell in advance which direction the flows travel in each line segment much less the quantity. Using pressure nodes in the calculations is the best way for the software to reach solution. Where two or more lines meet, the pressure will be exactly the same for each line at that junction. A slight change in pressure at a node can affect the calculations for many stream flows. While your model may be set up for single source and single sink, the software is made to robustly solve much more complex networks.

Edited by Pilesar, 15 May 2024 - 08:49 AM.