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GRE materials for FLOW LINES with hydrocarbon well production fluid-Contain high H2S

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FYS

Petroleum
Jun 24, 2008
22
Can GRE materials to be used for buried and above ground FLOW LINES with hydrocarbon well production fluid Contain high H2S (> 3% H2S and Co2 >3%) problem due to permiation of gases through the pipeline wall?
 
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They are routinely used in many places for such an application. The permeation issue would have to be evaluated in terms of the likelihood of exceeding any regulatory emission limits or creating an unacceptable HSE situation.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
I've not heard of problems with GRE in terms of gas permeation - PE type materials yes (though mainly HC liquids are the issue), but not GRE. Of course GRE has its issues as well, but that's not your question.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way
 
A reasonable evaluation should show it to be a low risk scenario. There have been BTEX issues with regulators in The Netherlands via threaded joints.

Water readily permeates PE and H2S comes with it - that's why there is venting required with special precautions.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
S Jones - Are you sure? Given that water utilities use PE a lot it seems "readily permeates" is a bit far. I just looked it up and found water permeation rates in higher density in the order of 10E-9 and lower. Low number hydrocarbons are known to be an issue with PE which is why they are not used much in flowlines or as liners, but I've not heard about issues with water.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way
 
We use them extensively in hydrocarbons and water - as liners which I neglected to clarify with respect to venting. Both liner applications require venting to relieve the annulus pressure caused by permeation. At what pressure is your permeation rated determined?

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
Steve, I understand about the venting of a liner, but this gas is normally light HC gas or volatile liquid which permeates the PE liner and can blow it inwards if the internal pressure reduces rapidly and it expands or vapourises. That's why liners in HC service or gaseous water service are problematic, but the water industry use tight fit liners for water pipes without venting or draining anything.

We've got off the subject of GRE though!

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way
 
Water does come through - perhaps the definition of 'readily' could be debated. The concept is related to the GRP question though - does the compound of interest come through the non-metallic material at a sufficient rate to cause unacceptable conditions. I haven't heard of it being an issue. We have some buried 120 bar GRP lines operating with 3% H2S and they don't set off H2S detectors.

Steve Jones
Corrosion Management Consultant


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