Corrosion of OCTG Pipe

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OCTG corrosion situation of oil, casing, gathering pipeline and storage tank corrosion is mainly oil and gas well output, shallow water, such as injection fluid corrosion, the main media such as H2S, CO2, dissolved oxygen and SRB.Tend to drill the role of many of the media, including drilling, pitting corrosion and corrosion fatigue, gravity stretching and rotating stress corrosion damage and fracture, etc.

OCTG corrosion characteristics of produced water has a sulfate-reducing bacteria, under deposit corrosion and erosion threaded carbon dioxide, bicarbonate and chloride ions, common causes of corrosion. When hydrogen sulfide occurs when the well (especially gas), tubing destroy hazardous characteristics, corrosion damage is mainly due to hydrogen embrittlement HIC and SSCC. Tubing in weight, under external pressure, and other factors in a complex state of stress, tensile stress is an important factor to promote the metal protective film and substrate corrosion damage. Tubing and gathering pipelines there fouling, when there Sr2 +, Ba 2+ dirt when not use conventional methods to clean pickling, seriously affecting the normal production. Tubing and gathering pipelines exist wax phenomenon, high frequency wax job seriously affect the normal production. Tubing and gathering pipelines of erosion-corrosion is a common form of corrosion failure, abrasive, cavitation, etc.

Basic measures of OCTG pipe corrosion
1) take appropriate and effective protective coating. Such as corrosion protection coatings and metal coating technology;
2) take other auxiliary instruments: such as adding inhibitor and a closed water system, reducing the amount of dissolved O2, CO2, H2S; the use of sulfate-reducing bacteria fungicides.
3) the use of cathodic protection, corrosion monitoring systems established to grasp the dynamic corrosion, preventive measures.