Aggressive environmental factors causing corrosion at gas production facilities in the presence of carbon dioxide

Issue 25(4) 2020
Pages 7-17

R.K. Vagapov, Limited-liability company «Gazprom VNIIGAZ», Moscow region, Russian Federation
D.N. Zapevalov, Head of Corporative Center, Limited-liability company «Gazprom VNIIGAZ», Moscow region, Russian Federation


Keywords: corrosion, carbon dioxide corrosion, aggressive corrosion factors, environmental conditions, corrosion rate

doi: 10.31615/j.corros.prot.2020.98.4-1

 

The current stage in the development of promising gas and gas condensate fields in the Russian Federation is associated with facilities whose production includes carbon dioxide. Such objects include the Urengoyskoye oil and gas condensate field (Achimov deposits), the Bovanenkovskoye oil and gas condensate field, and the Kirinskoye gas and condensate field. The presence of CO2 in the produced gas, in combination with moisture condensation and a number of other factors, stimulates the intensive development of local corrosion processes. The main factors that influence the development of corrosion at infrastructure facilities and its localization in the presence of CO2 are considered. It is noted that when assessing the degree of aggressiveness of the environment, it is necessary to consider not only the CO2 content, but also other basic operating parameters that can affect corrosion. During the exploitation of gas fields, the conditions of moisture condensation that contribute to corrosion arise, which occurs when a temperature gradient arises and the produced gas is rapidly cooled. Higher temperatures increase both the amount of precipitated moisture and, accordingly, the rate of local corrosion. Simulation tests have shown that the development of local forms of corrosion (pitting, ulcers) are possible even at low CO2 partial pressures (from 0,025 MPa and above) in the presence of condensed moisture.