Chemical Injection Sequence
Chemical Injection Sequence
(OP)
I am looking for a document that outlines the best practice for injecting the different chemicals in a pipeline.
We have corrosion inhibitor, biocide, and oxygen scavenger that have to be injected in the pipeline. What is the first chemical to inject, the second and the last?
Regards,
Corroneer
We have corrosion inhibitor, biocide, and oxygen scavenger that have to be injected in the pipeline. What is the first chemical to inject, the second and the last?
Regards,
Corroneer
RE: Chemical Injection Sequence
Passivation is the first step, not any of the three as mentioned.
DHURJATI SEN
RE: Chemical Injection Sequence
I usually do the following: the first injection point (the most upstream) for the corrosion inhibitor and the last one (most downstream) for biocide, but I am looking for a document/industry guideline that discusses such thing.
RE: Chemical Injection Sequence
RE: Chemical Injection Sequence
SiHyoung Lee
RE: Chemical Injection Sequence
But it seems rather extreme.
CI tends to produce a film on the inside to prevent corrosion, biocide deals with bugs / bacterial etc and Oxygen scavenger removes oxygen.
What is it you're transporting??
The last two tend to be used for hydrotest water when you're pumping out of a river or something similar and then in operation you just pump in CI.
To pump in the last two in operations seems rather odd.
But compatibility is key - get it wrong and end up with the dreaded "gunge"...
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RE: Chemical Injection Sequence
RE: Chemical Injection Sequence
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Chemical Injection Sequence
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Chemical Injection Sequence
Is there a materials break anywhere?
Normally I would want to have the Oxy scav injected and mixed in the last vessel before the pipeline so that the fluid is then at as low an O2 level as you can get before you start entering the presumably C Stl pipeline section.
What levels of O2 are you aiming for? You need to get down in the low (40-50 I think) ppb to be able to see any impact on C Stl. If your water hasn't been oxygenated then you'll be fine using oxy scav, but if it has then you need gallons of the stuff.
CI needs to go in about 10 to 15D upstream of any material break between say CRA and Carbon Steel if you're using a quill injection to allow it to start coating the pipe wall effectively.
Biocide is really for the downhole water to stop the reservoir going sour so could be anywhere along the system. So long as your pipeline doesn't stop for long periods in the warm you should be ok for biocide.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Chemical Injection Sequence
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Chemical Injection Sequence
And for the oxygen, some of the water comes from collection pits.
RE: Chemical Injection Sequence
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Chemical Injection Sequence