Predicting H2S ppm on oil/water by knowing H2S in gas

[elquesifilma]

All,

I am trying to predict the H2S content of produced water and oil at atmospheric conditions (tanks) by knowing H2S content of gas phase from my separator operating at 100 psig and 80F. This would help determine whether I need to specify NACE compliant materials.

Oil API gravity 40
SG. Water: 1.05
SG of gas 0.7 (H2S 100 ppm)

Should I assume that the oil liquid being sold contains 100 ppm of H2S, lower or higher?
Should I assume that the produced water that feeds the injection pumps is 100 ppm of H2S, lower or higher.

I understand I can get samples and analyze them, although I wanted to know if there is a close approximation or experience from someone on how to predict it.

Thanks in advance to all

 

[cloa]

This company says it has a partitioning calculator- try contacting them to get a login.

http://www.rawwater.com/seriatim/example.php

http://www.rawwater.com/control/contact.html

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[SJones]

The need for restriction on materials properties for sulphide stress cracking (SSC) is determined by H2S partial pressure in the gas phase. If the tank is liquid full consult Annex C.2 of Part 2. The term 'NACE compliant material' doesn't mean anything since ISO 15156-2 also deals with several other different cracking mechanisms. So you can then look at Figure 1 to decide about SSC, but what about Clause 8 regarding HIC?

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[bimr]

You need to know the pH of the solution. At a pH above 9, hydrogen sulfide dissolved in water is over 99% in the form of non-odorous hydrosulfide ion (HS), while at pH 5, only 1% is in the non-odorous form. If the pH is above 8, there is little trouble from H2S gas.