Sour Corrosion: Hydrogen Sulfide

Sweet Corrosion: Carbon Dioxide

CO2 is composed of one atom of carbon with two atoms of oxygen. It is a corrosive compound found in natural gas, crude oil, and condensate and produced water. It is one of the most common environments in the oil field industry where corrosion occurs. CO2 corrosion is enhanced in the presence of both oxygen and organic acids, which can act to dissolve iron carbonate scale and prevent further scaling.

Corrosion Predictions

CO2 corrosion of carbon steel used in oil production and transportation, when liquid water is present, is influenced by a large number of parameters, some of which are listed below:

• Temperature;

• CO2 partial pressure;

• Flow (flow regime and velocity);

• pH;

• Concentration of dissolved corrosion product (FeCO3);

• Concentration of acetic acid;

• Water wetting;

• Metal microstructure (welds);

Research on the Steel for Oil and Gas Pipelines in Sour Environment

Xiaodong Shao 1, 2*

1State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials, No. 89 Jinyeer Road, Xi’an 710077, China

2CNPC Tubular Goods Research Institute, No. 89 Jinyeer Road, Xi’an 710077, China