API 5L PSL 2 for CO2 Rich Gas?

[SmallInfo]

Hi experts
I read that API 5L PL2 is for sour services, is there any restriction on not to use API 5L PSL 1 for CO2 rich gas? I suggested API 5L PSL 2 for CO2 rich gas but my client asking for any reference from code in favor of using API 5L PSL 2 for CO2 rich gas.
Thanks

 

[SJones]

Why not look in "the code" that you are using for the pipeline design (assuming that it is a pipeline)?

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[LittleInch]

muhammad, You really need to consult a materials engineer as you appear to be out of your depth.

PSL2 is a higher grade of pipe with tighter chemical composition limits, additional testing and tighter mechanical limits. It is normal for this type of pipe to be used in oil and gas pipelines.

"Sour" normally means H2S or similar components, not CO2. CO2 with free water can be corrosive, but doesn't affect the pipe material in the way H2S does.

PSL2 pipe is only able to handle this if you add Annex H for sour service. You cannot add Annex H for PSL1 pipe, only PSL2 pipe

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SmallInfo]

SJones, I am following B31.4 and it says that

 

[SJones]

@Muhammad
OK - if you are using B31.4, then you have supercritical CO2, and I can't see PSL 1 being acceptable for that. CO2 is transported in carbon steel pipelines - what has your corrosion assessment told you about the suitability of carbon steel? A simple Google search for CO2 transport pipelines will give you some background to discuss with your client.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[SmallInfo]

SJones, thanks, yes its super critical but the problem is my client asks for references from codes, either I suggest API 5L PSL 1 or 2 he will ask for reference from code and as much as I know (after reading API 5L) I am unable to provide any reference from code, its confusing for me as a junior engineer, may be its easy for you guys but challenging for me.

 

[LittleInch]

Oh, it's CO2 - I thought it was just normal methane with some CO2 in it.

Like I said - you're in too deep and you need help from others - a junior engineer is not expected to deal with this direct to a client.

If this is dense phase CO2, then your issue is low temperature ductility i he event of leak leading to full scale rupture.

What exactly are you transporting at what pressure and temp?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SmallInfo]

LittleInch, thanks, its gas with condensate coming from well and its rich in CO2, pressure is 300psi and temperature is 100F.

 

[EdStainless]

This is complicated, how much water? how much CO2?
As the pressure goes up the CO2 dissociates more in the water lowering the pH further.
This acid will attack the inside of the pipe.
Ask the client, ultimately it is his responsibility. If he has hired you explicitly to do this then you need to find and expert.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[SJones]

@Muhammad
Now you have flipped back to multiphase hydrocarbon. It’s apparent that the issue is a bit beyond you. You will not find anything in the codes because, as you show in your copyright infringement, codes do not address weight loss corrosion issues caused by CO2. That is the domain of the corrosion engineer. Perform a search of Eng-tips for the term “CO2 corrosion modelling”

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[LittleInch]

Muhammad,

You might think we're not trying to help you but we are - you need to give us more information though.

So can you post or list the components of the gas and liquid phase of the well fluids in the pipeline please.

Also what is your role in the project and what support do you have?

"Sour" service means above a certain (low) amount of H2S. Then you need API5L pipe to Annex H (Sour service) Annex H only applies to PSL2 pipe.

If however you have high concentrations of CO2 (> 0.5%) then you have issues with corrosion as well fluids will have water. If not free water then water will condense in the pipeline as it cools.

CO2 is sometimes referred to an an "acid" gas and this may be confusing your client and you??

SO give us some more information, answer all the questions we have all asked and then we might get somewhere.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SmallInfo]

LittleInch, thank you so much to understand exactly what the situation is, I will get back to you as soon as I get some data. I am the only mechanical engineer in this small office my two seniors moved to another organization and now I have to do everything, I have zero support here, they are looking for someone senior to join, till then I have to do everything.
Thanks again

 

[MJCronin]

Is it just me, or do all of these posts have the same general themes ?

- Newbie placed in a job he hardly can do or understand.

- Newbie working alone, no one to consult with, ...No mentoring or staff .... zero support (as stated above)

- Newbie under extreme duress asking "Where does it say in the Codes that I must do X or that I cannot do Y ?'

- Quickly learning Newbie of course, gradually understanding the dire parameters of his plight and how he needs more information

- Evil MBA/PMI boss unhappy with his performance threatens him with dismissal

Tell me I am wrong in this general characterization ???

Anybody out there in "Engineering Geezer Land" agree with me ?

MJCronin
Sr. Process Engineer

 

[weldstan]

Agree with MJCronin. It's a pity that inexperienced engineers are requested to perform in areas requiring an experienced engineer in another discipline. Gone are the days of my initial work where I had plenty of mentors to assist in my development. REDUNDANCY IS OUT!

 

[SmallInfo]

MJCronin, My non-technical boss thinks engineering is easy and its written in the code what should be done and what should not, there are threats, exploitation and much more we have to face, we have no options available at the moment to say NO to our organization, we are working 12 hours a day without compensation, this is what we are going through.
Kindly bare with me if I ask more questions.
Thank you all

 

[SJones]

@Muhammad

All posters, including MJCronin, are actually sympathising with your plight. If we can go back to your originating post, is the crux of your question: Can I use PSL1 pipe (as directed by my boss) for CO2 rich multiphase hydrocarbon, or do I have to use PSL2 (as I think but have to justify to my boss)?

(this is without suggesting that, if there is a gas phase present, the code should really be B31.8)

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[weldstan]

One must also ask, is this pipeline upstream or downstream of a liquid-gas separator? How much water is in the fluid stream? PSL1 type piping has been used in CO2 rich gas piping when little or no water is present in past similar pressure/temperature applications.

 

[blacksmith37]

Supercritical CO2 is a very special case ; running ruptures can occur ( for miles) as the pressure does not drop to zero at a rupture ; unrelated to corrosion. External crack arrestors are used , one type is "clockspring". Pipe toughness is also critical. Such lines have been built, you need a literature search to avoid reinventing the wheel.

 

[SJones]

@blacksmith

We seem to have developed the scenario that this is a multi phase hydrocarbon pipeline at 20 bar with some, as yet, undefined amount of CO2.

We are still trying to determine the exact question, but it appears to relate to whether ASME B31.4 will define which linepipe PSL applies, and how much corrosion allowance is needed.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[SmallInfo]

@weldstan, Thanks for reply, its upstream, I emailed this question to my client and waiting for his reply.