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[Jiten_process]

Dear All,

 

I would like to have expert views on the subject matter. I was referring a book "Petroleum and Gas field processing" By Hussein K. Abdel-Aal, Mohamed A. Aggour, Mohamed A. Fahim and I came across defination of "sour" crude as below

 

 "crude oil is considered "sweet" if the dangerous acidic gases are removed from it. On the other hand it is classified as "sour" if it contains as much as 0.05ft3 of dissolved H2S in 100gas of oil. "

 

If we convert it in to vol%, it would be around 0.37%

 

However many literature mentiones this limit as 0.5%.  For example refer below online doc

 

http://www.investope...s/sourcrude.asp

 

I checked with NFPA-0175, they have mentioned limit as 0.05Psia partial pressure and for liquids they have suggested method to calculate this values in annex C, C.2. 

 

My question is what is the correct value and reference in which this value is defined. 

 

Thanks. 

Edited by Jiten_process, 19 May 2014 - 05:39 AM.

[PingPong]

You are mixing up two different situations here.

 

I am not working in the oil production industry, but in the design of refineries (and other plants) that process crude oils.

 

For me in the oil processing industry a sweet crude is one with a low sulfur content, and a sour crude is one with a high sulfur content. That is also what investopedia.com is telling you. The sulfur is chemically bound to the hydrocarbons of the oil.

 

In the oil production industry they probably look at it differently: the oil coming out of the well always contains H₂S and they may define the oil based on its H₂S content, which is what the book "Petroleum and Gas field processing" seems to do.

 

The H₂S is removed from the crude oil by stripping before it is shipped to refineries all over the world.

After stripping the H₂S, the production engineer may call it sweet oil (because of its now negligable H₂S content), but the refinery processing that crude oil may call it sour because of its high sulfur content.