Study on Corrosion Behavior of 20#Carbon Steel in Simulated Produced Liquid of Alka-li-free Composite Flooding
The alkali-free composite flooding(compound salt,polymer,and surfactant)is a new and improved technology that can effectively enhance recovery with low-cost and reduce pipeline scal-ing.However,with the gradual increase of the concentration of agent exposure in the gathering and transportation system,the adaptability of the 20#carbon steel(without internal anti-corrosion)using in gathering and transportation pipeline currently is not clear for the future produced liquid.To investi-gate the corrosion behavior of 20#carbon steel in the produced fluid,according to the concentration prediction of the alkali-free composite flooding ternary return produced fluid provided by a production capacity construction project in a certain block of Daqing Oilfield,based on the indoor simulation of the on-site gathering and transportation system working conditions,the corrosion behavior of 20#car-bon steel in alkali-free composite flooding simulated produced fluid is clarified through dynamic corro-sion simulation tests and electrochemical tests.The results show that the corrosion rate of 20#carbon steel specimen in the simulated solution with the highest concentration is relatively high,and the corro-sion grade is moderate,while the corrosion grade in the current produced liquid and remixed water is low.There is obvious passivation phenomenon on the surface of the specimen,as Cl-could quickly penetrate the passivation film,resulting in a short passivation time,and accelerating the corrosion elec-trode reaction.Considering the large amount of Cl-present in the gathering and transportation pipeline in the future,the electrochemical reaction becomes more complex,which will result in the aggrava-tion of the corrosion in the pipeline.Therefore,it is recommended to take appropriate internal corro-sion protection measures in gathering and transportation pipelines.
20#carbon steelalkali-free composite floodingsimulated produced liquidcorrosion behavior
万方数据
维普
