Scale chemical analysis

[bpownall]

I was hoping some chemical engineers with experience couuld offer assistance on a question about scale/schmoo. I am working in a oil field to determine the best recipie to clean our main water injection lines which have been restricted over the years. A chemical analysis on the stuff shows that it is:

Hydrocarbons: 10%
Soluble salts: 1.40%
Calcium carbonates: .84%
Iron compounds 65.08%
Acid insolubles: 22.91%

Iron compounds were iron sulfide and iron oxide. I am getting a second test done to confirm the findings.

What are some options to clean this line? I would appreciate a variety of chemical options/procedures that I can test by flushing. My project is to focus on creating the best "recipie" to clean our lines. More options to test, the better.

Thank you for your help, I do not have much experience yet and am a first year engineer.

-Brian

 

[ash9144]

Perhaps a weak acid solution such as citric acid or even nitric.

I don't know what the acid insoluble would be except maybe tars built up over time. These may be removed by steaming or blowing with nitrogen.

 

[SJones]

Contact the specialist pipeline service companies for their recommendation.

Steve Jones
Materials & Corrosion Engineer

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

 

[bpownall]

Steve,
we have talked before briefly about the possibility of pigging the lines. Several people here I mentioned it to had never heard of pigging water injection lines.

 

[SJones]

Judging by your nickname and the use of the word 'schmoo', I am assuming that you are on the North Slope with a company that has the word 'British' in its title. If this is the case, get hold of Sunbury report, ESR.96.ER.075, Corrosion & Materials Issues In Water Injection by J Smith and I Vance and focus on Section 10 Maintenance Pigging. Here is a quote to start you off:

"Kuparuk (Arco operated oil field on the North Slope)carried out tests to determine the optimum pigging frequency of water injection lines. By measuring the rate of buildup of solids, it was determined that the optimum frequency for seawater injection lines was 3 monthly and monthly for produced water lines. This is the frequency adopted at Prudhoe Bay"

Steve Jones
Materials & Corrosion Engineer

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