corrosion inhibition points

[KMur]

Dear all,
In oil export pipeline (120km length), at present we are injecting corrosion inhibition at starting point of pipeline. Client wants to add more injection points , is there any basis to add these points based on length?, Please provide any standard to implement these points.

thanks

 

[brimmer]

There is no standard that will tell you where to put chemical injection points, perhaps some rough guidelines, but you have to use judgement. I don't understand why you can't get residual chemical concentrations at the receipt point of the line, that will tell you if and how much chemical is making it through.

 

[KMur]

Dear brimmer,
Thank you very much.
How can I get the residual chemical concentration? Can I get from chemical supply vendor? Please suggest me.

 

[LittleInch]

Give the minute amounts of CI injected, I think it will be difficult to get a residual quantity at the end.

You really need to take advice from your supplier as to the effectiveness of the chemical over distance.

What I have seen commonly at the start of the pipeline operation is a batch of CI between two plugs to provide an initial film of CI on the walls and then regular injection keep it "topped up". Sometimes companies batch pig with CI every year or two to make sure.

however if client wants to overdose his line then so be it, but this sort of thing is so specific to your product, fluid velocity and specific type and manufacture of CI there is no "standard" AFAIK. I've rarely seen another CI injection point in a 120km pipeline other than at the start, unless a large flow entered part way along.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[brimmer]

Yes, the chemical provider normally completes this work. Ask them if they can get a residual. Although I see you say "export" oil line, which might mean you don't have much free water. If you have enough water, you can certainly get a residual chemical concentration. Typically for that distance, 120km line can be protected from one injection point, just have to make sure there is enough of it injected to get to the end. Adding more points won't do any harm, but may add costs they don't really need.

 

[SJones]

The end user might do better to examine the pigging programme and procedures rather than pour more chemical into the line. In order to help them out, you need to understand why they think that they need more chemical injection: what exactly is the problem.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

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

 

[KMur]

Thanks to all.
Yes. Eventhough Export oil is not corrosive since it was treated, our PMC people are forcing to keep more than one injection point since they are expecting more corrosion without any reason. We have to fulfil their requirement or need to give justification that one point is adequate.
I am trying to contact chemical supplier.

 

[SJones]

The chemical supplier will tell you that you need more chemicals

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

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