Corrosion Resistance Of Super13%Cr Tubing Materials Under The High Temperature And High Pressure Environment Of Oilfield

Aautoclave tests and SEM, EDS, XRD, XPS technologies were used to study CO2and H2S corrosion behavior of super13Cr steel tubing under the high temperature and pressure environment,and CO2corrosion mechanism of super13Cr steel. The galvanic corrosion and crevice corrosion of super13Cr tubing steel was also investigated.The results showed that in CO2corrosion environment, with the temperature and Cl" concentration increased, uniform corrosion rate of super13Cr steel increased subsequently. Around the temperature of150℃, the maximum appear and is0.0164mm/a, but its corrosion rate is far less than0.1mm/a. As the temperature increases, the local corrosion of super13Cr steel is rising, in the temperature of150℃, its largest local corrosion rate can reach1.1049mm/a. With the rise of CO2partial pressure, uniform corrosion rate of super13Cr increased at first then decreased. The major components of the corrosion films were amorphous compound Cr2O3.In H2S coexistence corrosion environment, with the rise of temperature, uniform corrosion rate of super13Cr increased at first then decreased. In CO2and H2S coexistence corrosion environment, with the rise of temperature, uniform corrosion rate of super13Cr changed a little at the temperature of lOO℃. When the temperatu-re to160℃, the comprehensive corrosion occurred, corrosion rate increased obviously;The major components of the corrosion films were compound FeS.In the selected test conditions, super13Cr steel has good resistance to SSC performance.In the simulation galvanic corrosion test of the small sample, the test results of galvanic corrosion of super13Cr and P110show that P110happen serious local corrosion. Physical experimental results and small sample experimental results are consistent.In the simulation crevice corrosion test of the small sample, the super13Cr steel has good resistance to crevice corrosion ability. In the physical experiments, the pipe couplings, tube body and joint (sealing shoulders) of super13Cr did not appear local corrosion phenomena of pitting corrosion, crevice corrosion, and with the small sample simulation experiment results are consistent.