SONG Chengli, SONG Xiaojun, CHEN Qingguo, LI Kun, JIA Haidong, LI Guangshan
The high temperature and high pressure dynamic reactor was used to simulate the actual working conditions of CO2 and H2S coexisted environment in oil and gas field. The corrosion behavior of 20 steel at different CO2 partial pressures (0.01, 0.05, 0.21, 0.50 MPa) and H2S partial pressures (0.000 3, 0.003, 0.01, 0.05 MPa) and the degree of influence of CO2 and H2S partial pressure on uniform corrosion and pitting were studied by corrosion tests. The results show that under H2S partial pressure of 0.003 MPa, when CO2 partial pressure was 0.01, 0.05 MPa, uniform corrosion of 20 steel mainly occurred; with increasing CO2 partial pressure, pitting became serious. Under CO2 partial pressure of 0.05 MPa, when H2S partial pressure was 0.000 3 MPa, 20 steel's surface corrosion was slight; with increasing H2S partial pressure, the corrosion was intensified, but still uniform corrosion mainly occurred. H2S and CO2 partial pressure had a very significant impact on 20 steel's uniform corrosion rate and pitting rate; H2S partial pressure had a relatively great effect on uniform corrosion, and CO2 partial pressure had a relatively great effect on pitting.
