Re: Effects of carbonic acid on a Natural Gas Storage field

Arlon,
Carbonic acid is considered a "weak" acid.  Even though it is a weak acid 
it will corrode steel under the right conditions.  The high pressures 
which are present in the pipeline only increase the acidity of the acid.  
One major requirement is that water must be present in the system.  The 
CO2 in the gas stream dissolves into the water and makes carbonic acid.  
And the acid reacts with the walls of the pipeline.  What makes the 
situation worse, is that everytime a molecule of carbonic acid reacts with 
the steel another molecule of CO2 dissolves into the water to replace the 
one that just reacted.  And you virtually have an endless supply of CO2 in 
the line.  Since the water flows on the bottom of the pipeline, the bottom 
is more susceptible to the corroion.  There is a world of information 
regarding CO2 on the internet.  You may want to visit the NACE (National 
Association of Corrosion Engineers) website to get more information.  But 
the leading book for pipeline operators is by a man called Peabody.  I 
wish I could give you more information, but NACE will have reference to it 
and you can also purchase it from NACE.  If you need more information, I 
work at Williams-Southcentral and my e-mail is 
J.Carlin.Gregory@Williams.com.

Hope this helped out!