Corrosion Behavior of N80 Steel in Simulated Oxygen-reduced Air Flooding Production Well
In order to explore the corrosion behavior of N80 steel in oxygen-reduced air flooding production wells,the main controlling factors of corrosion in a domestic oxygen-reduced air flooding production well were analyzed based on the grey relational analysis method.Taking the reservoir simulation results as laboratory simulation parameters,the corrosion behavior of N80 steel in different production periods was studied by dynamic weight loss method combined with metallographic microscope,XRD,3D morphology.The results show that the oxygen content is the most sensitive to the corrosion of the production well with oxygen-reduced air flooding.Under the oxygen containing condition,the corrosion rate of N80 steel increases significantly,and the corrosion rate when the oxygen content is 3%(0.3 MPa),which is about 5 times than that without oxygen.In the initial stage of oil displacement,the corrosion is localized corrosion dominated by CO2,and the corrosion products are mainly dense FeCO3.With the prolongation of gas injection time,the wellbore is in a balanced environment of CO2/O2,and the corrosion transforms into the combined action of the two.The corrosion products are FeCO3 and loose and porous Fe2O3.After 3 years of continuous gas injection,the production well is in a high O2+low CO2 environment,the dense FeCO3 is destroyed,the corrosion pit develops laterally,and the corrosion transforms into a general corrosion dominated by O2.
N80 steeloxygen-reduced air floodingproduction wellboregrey correlation analysisO2/CO2 corrosion
万方数据
维普
