2 replies to this topic

[phoroogh]

Hi everyone,

I have recently encountered a situation in which API reported by hysys is different from what can be calculated manually. I have a three phase oil stream (gas+oil+water) @ standard conditions (60F and 1 atm). 

As you see in the following screenshots, API is reported to be 25. However, by considering the densities of water and oil at that conditions and the formula "API=141.5/SG - 131.5", 12 will be achieved.

I do not know what the problem is. Isn't hysys calculating API according to the formula?

I appreciate your help in advance.

 

 

 

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[Pilesar]

Perhaps Hysys ignores the water when calculating API(petrol) value. Otherwise, why include 'petrol' in parentheses? Contact the software tech support for definitive answer.

[phoroogh]

Perhaps Hysys ignores the water when calculating API(petrol) value. Otherwise, why include 'petrol' in parentheses? Contact the software tech support for definitive answer.

Thanks for your reply. I ignore the water as well when calculating API manually. In fact, the liquid phase in Hysys only contains oil and I divide its density @ 60F to the density of water (the aqueous phase) @ 60 F to achieve the specific gravity needed for the calculation of API.