Olga Simulation for Dynamic Pipeline Transportation

[johndoe_123]

Hi there, I am trying to run a dynamic simulation for the flow of binary mixture CO2+H2O to predict hydrate formation over a period of 24 hours operation. I have modelled the fluid mixture in Multiflash and inserted it as PVT, mfl, and hydrate curve file in OLGA (as compositional tracking module is used). All hyrdate FA models (HYDRATECHECK, HYDRATEKINETICS, HYDRATEOPTIONS) have also been chosen for each flowpath. However, the file was not runnable as there was an error with the following warning:

Error[0] HYDRATEKINETICS: Component Methane (C1/CH4/Methane) and/or Water (H2O/Water) is not defined. It is not possible to use the HYDRATEKINETICS module without Methane and Water when COMPOSTIONAL is set to ON.

Am I not supposed to use the compositional tracking module for this case? Or is the model I applied in Mutiflash (CPA Infochem) not suitable for this simulation?

Thanks all, in urgent need of assistance for this error!

 

[LittleInch]

It doesn't seem to work with CO2.

Does co2 and water create a hydrate??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[johndoe_123]

Some studies show it does...this is what I'm trying to figure out for CCS transportation system.

Does this mean I cannot use CO2 in the composition tracking module?

 

[LittleInch]

You need to ask the supplier, but that error message tells me it doesn't.

Normally you really really don't want free water and co2 due to the corrosion issues you get. I've never heard of hydrates being possible in CCS transportation, but you could be right. Got any links to these studies?

You do get two phase flow in CCS co2 due to the impurities. But hydrates?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

Abstracted from the GPSA in the chapter on Dehydration:

"There are three recognized crystalline structures for such hydrates. In both, water molecules build the lattice and hydrocarbons, nitrogen, CO2 and H2S occupy the cavities. Smaller molecules (CH4, C2H6, CO2, H2S) stabilize a body-centered cubic called Structure I. Larger molecules (C3H8, i-C4H10, n-C4H10) form a diamond-lattice called Structure II."

Also

"The presence of H2S in natural gas mixtures results in a substantially warmer hydrate formation temperature at a given pressure. CO2, in general, has a much smaller impact and often reduces the hydrate formation temperature at fixed pressure for a hydrocarbon gas mixture."

 

[johndoe_123]

This was some of the references that discussed about hydrate formation prediction in CO2 transportation:

https://iopscience.iop.org/article/10.1088/1755-1315/804/2/022001/pdf

https://pubs.acs.org/doi/abs/10.1021/acs.energyfuels.3c01985

I have succeeded in making the simulation run, but I can't figure out why the hydration formation pressure is negative (-200 bar) now...

 

[LittleInch]

Minus 200 bar????

Doesn't exist.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Are you using P-T or P-H?

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