抗硫套管钢P110SS在高含H_2S/CO_2环境中的腐蚀行为和硫化物应力开裂敏感性研究

Corrosion Behavior and Sulfide Stress Cracking Sensitivity of Sulfide-resistant Casing Steel P110SS in Hyperbaric H_2S/CO_2 Environment

利用高温高压反应釜模拟普光气田的工况环境,研究抗硫套管钢P110SS在高含H2S/CO2环境中的腐蚀行为和硫化物应力开裂(SSC)敏感性.结果表明,随着温度和H2S/CO2分压的升高,P110SS的腐蚀速率先降低后升高,而在相当于井中部工况的环境中,钢的腐蚀速率最低,腐蚀产物膜明显脱落.在高含H2S/CO2环境中,采用四点弯曲法加载达到P110SS屈服强度的90%时,试样表面未发现裂纹,表明SSC敏感性比较低.

The corrosion behavior and sulfide induced stress corrosion cracking sensitivity of a sulfide-resistant casing steel Pll0SS in hyperbaric H2S/CO2 environment were studied by high temperature/pressure reactor which simulated the operating environment of Puguang gas field. The corrosion rate of P110SS in hyperbaric H2S/CO2 environment decreased first and then rose with the increase of temperature and partial pressure of H2S/CO2. Corrosion product peeled off in an environment corresponding to the middle area of the well where the corrosion rate was minimal. The sulfide induced stress corrosion cracking sensitivity of Pll0SS steel in hyperbaric H^S/CO2 environment was very low revealed by four point bending test for the steel with a load of 90% yield strength, which could be attributed to the uniform tempered microstructure of sorbite with fine grain, high dislocation density and uniform dispersion of carbides of the steel.