Effects of H2S on BeCu 1

[TexasSRT]

I am looking for anyone that can help with the specific effects that H2S would have on BeCu in an oilfield drilling application. Thank you

 

[Maui]

Your question is much too vague to provide an intelligent answer. What is the BeCu to be used for in an oilfield drilling application? H2S in what concentrations? Exposure over what period of time? Under what conditions? To meet what specification requirements? You need to be much more specific.

http://www.EngineeringMetallurgy.com

 

[TexasSRT]

My apologies for the lack of information.

The BeCu is used in the construction of tool housings for Directional Drilling MWD Downhole Steering tools. They are tubular housings approx .250" in thickness. Exposure to H2S timeframe is varied from several hours to several days. The temperature ranges from 80-125C with downhole pressure ranging from 500-5000 PSI. Unfortunately the concentration of H2S also varies greatly during the driling process.
What I was looking for was an explanation of how H2S effects and causes damage to BeCu. How it changes the properties of the alloy and what overall damage could be expected. We had some tools recently that were exposed to H2S during drilling operations and an explanation to go with the physical apperance is what I was hoping for.

 

[Maui]

The grain boundary regions in the BeCu containing oxides are the most likely areas to suffer from hydrogen damage because hydrogen reduces copper oxide to form water. When the reaction takes place at temperatures above the critical temperature of water, the copper oxide inclusion is replaced with steam which is virtually insoluble in copper. The resulting steam pocket or bubble exerts a pressure on the surrounding metal producing a bubble or gas pocket. The oxide inclusions that reacted with hydrogen to form steam are generally associated with grain boundaries thus continued bubble development tends to force the grains apart. As these gas pockets coalesce, intergranular fracture can result. See

http://www.sandia.gov/matlsTechRef/chapters/4001TechRef_Cu.pdf

In order to protect against this type of failure mechanism, oxygen free BeCu should be specified.

Maui

http://www.EngineeringMetallurgy.com

 

[metengr]

Also, look here

http://www.google.com/url?sa=t&rct=...iJPqqxmlWd9mri-kmQ-uZNw&bvm=bv.41018144,d.eWU