Connection Seal Pitting

[eltooon]

We recently observed serious pitting on connection seal area of a pulled-out completion tubing string. The pipe is internal coated API L80 grade. The string is in hole for 6 month only.

What may be the possible reasons? Anyone has an idea?

 

[cloa]

What fluids experienced in your completion string? What internal coating?

 

[eltooon]

Fluid: brine + corrosion inhibitor
Coating: TK-236

Light corrosion on string OD and ID, and still in relatively good condition. Yet corrosion on seal area is surprising.

 

[EdStainless]

There may have been no inhibitor in the seal area. The tight crevice sets up serious local corrosion issues.

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Plymouth Tube