How do I calculate the corrosion rate

[RogerF]

Hello!
Need some help!
How do I calculate the corrosion rate for raw seawater injection into a well trough the tubing, when the variables are the water speed (flow rate) and the temperature?
The pressure is constant and the tubing material is carbon steel ST52.
I will also inject biocide, scale and corrosion inhibitor, but I have to find out the worst case. (Oxygen is not being removed).

Does anyone know if there is a formula that I can use for this calculation?
What can I do to resolve this problem?

I am also trying to get more information and experiences around corrosion problems upstream and downstream, but also generally seawater injection.
Does anyone have experience numbers for corrosion rate?

Downstream: O2 corrosion, erosion corrosion,
Upstream: H2S corrosion

hope someone can help me!!

Best Regards
Roger

 

[6240]

DEar Roger,
You have the worst scenario possible: seawater, scale inhibitor, carbon steel, and even different temperature (this is a killer). I don't know formulas for calculation but I would suggest you replace your carbon steel piping with stainless steel (I think the 400 series is for seawater, do a little bit research on the internet) with cathodic protection of the piping. What you have won't last even two year (it is my opinion). Better yet, you may consider using PVC or fiber glass (with proper installation) piping. They are supposed to be more resistant to any chemicals and rotting. You may want to check with the NACE (National Association of Corrosion Engineers) if they have a web site.
Good Luck.

 

[NickelMet]

Roger:

Try NACE as the previous post suggests. They have a public forum board on which you can ask the same question.

http://nace.org/nace/index.asp

(Main Site)

http://nacecorrosionnetwork.com/cgi-bin/lyris.pl?enter=nace&text_mode=0&lang=english

(Message Board....if the link works)

Enjoy
BDR