RILSAN® Polyamide 11 in Oil & Gas Off - HCL Fasteners Ltd

3.8 Compatibility of RILSAN® BESNO P40 TLX and
BESNO P40 TLO resin with various offshore fluids
and chemicals
A variety of offshore fluids have specific functions in the exploration
and production process in offshore installations:
• Demulsifiers to break oil/water emulsions
• Corrosion inhibitors to slow corrosion of steel
• Bactericides to suppress the formation of acid-creating
bacteria
• Paraffin inhibitors which prevent the crystallization of
paraffins leading to a blocking of the pipes
• Scale inhibitors which prevent the formation of salt scales
capable of blocking of the pipes
• Oxygen scavengers which help prevent corrosion
Numerous formulations exist depending on the producer and
specific adaptions. However, the nature of the ingredients
remain essentially the same. Often even the compounds remain
the same and given formulations differ only in the amounts of
the constituents. The aim of this chapter is to analyze the behavior
of PA11 when exposed to the specific chemicals used in offshore
applications. It supplements the information in the more
general chemical resistance table in section 3.4.
For convenience, the results of the testsoftypical offshore fluids
are summarized in a final subsection 3.8.9.
For the screening tests, small dogbone samples were autoclaved
at a given temperature immersed in the chosen offshore fluid.
After a given time, 5 samples were retrieved on which tensile
testswere performed, weight changes monitored, and the
molecular weight changes analyzed.
Allcompatibility tests were performed at 60°C. Testing periods
were generally 2 years.
Given the typical activation energy for the chemical degradation
processes, a good behavior after 2 years at 60°C should give a
service life over 20 years at temperatures around 20°C.
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