Materials Capable of Withstanding 420,000 PPM H2S

[tsb15]

Any recommendations of high strength (90 ksi or so) materials capable of withstanding 420,000 PPM (42 %) H2S and 8 % CO2 at 400 degrees F (bottom hole temperature) at 17,000 psi pressure (bottom hole pressure) for an oilfield downhole application? We typically use 4140 HT or 17-4 PH stainless at H900 condition for our downhole tools, but these will become hydrogen embrittled. Thanks in advance for any ideas!

 

[EdStainless]

A cold worked "C" type alloy (C-22, 59, 686) is about the only option that I have seen used in this type of service.

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[CoryPad]

Multiphase alloys like MP35N are used in down hole applications.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SJones]

The tools will only become hydrogen embrittled if there is a chemical reaction to generate hydrogen upon their surfaces. At those pressures and temperatures, what reaction will generate hydrogen?

The first question to ask is: will these tools see any liquid water? The second is: are there any chlorides around? The third is: any elemental sulphur?

Armed with that knowledge, one can then look at ISO 15156.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[dcasto]

If the gas is supersaturated and free water around, then an Inconel could be used. The Lost Cabin Field has had papers on the metalurgy used there with 25,000 foot wells producing 50% H2S gas.

 

[Spiralis]

We have had sucess with Inconel 625 that had a minimum specified yield strength of 80ksi. Hardness was still below the max specified in ISO15156. The well was approx 10.000psi, 18% H2S, 150deg C. Do not know the amount of chlorides and CO2, but I know these elements were present.

The "C" alloys are probably not strong enough. Age-hardening of Inconel 625 is one option you can try out.

 

[0707]

?HIC-resistant steels can be used to minimize the susceptibility to blistering and HIC damage by H2S.

Detailed materials and fabrication guidance can be found in NACE Publication 8X194.


Regards

luis marques