Synthesis of polyamide chitosan and investigation on inhibiting corrosion of completion fluid

Abstract

The offshore completion fluid has the characteristics of complex composition and high salinity. In order to solve the severe corrosion of underground pipelines causing by completion fluid. In this paper，a polyamide chitosan（PACS） was synthesized from the natural polysaccharide chitosan，and its corrosion inhibition performance on carbon steel was investigated. The results of weight loss corrosion experiments showed that after adding 2 000 mg/L polyamide chitosan to the completion fluid at 80 ℃，the corrosion rate of carbon steel decreased from 3.852 to 0.072 mm/a，and the corrosion inhibition percentage was 98.13%. In addition，electrochemical tests（potentiodynamic polarization and Nyquist curve） also showed that when the concentration of PACS reached 2 000 mg/L，the corrosion inhibition percentages was more than 90%. PACS shows good corrosion inhibition properties of carbon steel.

Keywords

• completion fluid
• chitosan
• polyamide
• corrosion inhibitor