Choke modeling using OLGA

[ginsoakedboy]

I am trying to simulate the J-T cooling at Choke valve during Subsea tree startup using OLGA. I have some questions:

1. Is OLGA the right tool to perform a transient simulation of Choke opening operation?

2. What is critical flow in the context of a Choke Valve? Does criticality of flow affect J-T cooling (or heating)? Is it related to the inversion temperature?

3. I am trying to find typical values of parameters so my calculations will be fairly representative of the different field conditions. Will the black oil model be a good approximation?

4. Generally speaking, are production fluids with high proportion of oil are more susceptible to J-T cooling? Or, the ones with higher gas percentage?

5. During a well startup, what might be "maximum ?P" across the Choke? I imagine the maximum ?P is experienced immediately after the Choke is cracked open.

6. During full blown production, what may the ?P across the Choke?

Thank you all in advance,
S.

 

[sailoday28]

j-t is for constant enthalpy. For adiabatic steady state flow, j-t can be used if change in kinetic energy is small.

For transient conditions, dependent upon size of smaller flow area, the critical pressure ratio may not be the same as steady state.

Regards

 

[ginsoakedboy]

I am aware of the theory, but have not used OLGA before. Also, I need advice from someone who is a bit more experienced in dealing with Subsea Production Chokes in the field. Thank you.

 

[MortenA]

Maybe you should ask Scanpower (the vendor)?

Best regards

Morten

 

[Ussuri]

Try the flow assurance forum?

 

[zdas04]

Just repeating the post in the Flow Assurance Forum is a good way to get one or both threads deleted.

David