Abstract:Varying degree of corrosion occurred in internal and outer wall of tubing string.Serious corrosion is found in some well deep.The results of chemical composition analysis,metallurgical structure test,SEM,EDS and XRD show that chemical composition and metallurgical structure of the tubing meet the API Spec 5CT standard requirement.Large corrosion products stack at the bottom of the pitting.Cl- enriches under the corrosion product layer.Corrosion product in internal wall are FeCO3,MgFe(CO3)2,FeO(OH),Mg3Ca(CO3)4 and Fe3O4,that in outer wall are FeCO3,MgFe(CO3)2,CaCO3 and FeO(OH).Internal wall are damaged by CO2 corrosion.Corrosive gas and medium come into the space between casing string and tubing string corrode outer wall of tubing.Tubing around 3279 meter is most hardly affected because it is at the temperature which CO2 corrosion is most seriously.Cl- enrichment is the important reason inducing local corrosion.
赵国仙, 吕祥鸿, 韩勇. 某井油管腐蚀原因分析[J]. 材料工程, 2010, 0(3): 51-55.
ZHAO Guo-xian, LU Xiang-hong, HAN Yong. Analysis of the Reason on Tubing Corrosion Failure. Journal of Materials Engineering, 2010, 0(3): 51-55.
[1] WAARD C DE,LOTZ U.Prediction of CO2 orrosion of carbon steel[A].A Working Party Report on Prediction CO2 Corrosion in Oil and Gas Industry[C].London:The Institute of Materials,1994.30-58. [2] ZHOU S,STACK M M,NEWMAN R C.Electrochemical studies of anodic dissolution of mild steel in a carbonate-bicarbonate buffer under erosion-corrosion conditions[J].Corrosion Science,1996,38(7):1071-1084. [3] DUGSTAD A.Formation of protective corrosion films during CO2 corrosion of carbon steel[A].Advanced in Corrosion Control and Materials in Oil and Gas Production[C].London:European Federation of Corrosion Publication,1994.70-76. [4] HAUSLER R H,STEGMANN D W.CO2 corrosion and its prevention by chemical inhibitor in oil and gas production[A].Corrosion/88[C].Houston,Tx:NACE,1988.363. [5] LINTER B R,BURSTEIN G T.Reactions of pipeline steels in carbon dioxide solution[J].Corrosion Science,1999,41:117-139. [6] IKEDA A,VEDA M.CO2 corrosion behaviour of Cr-containing steel[A].A Working Party Report on Prediction CO2 Corrosion in Oil and Gas Industry[C].London:European Federation of Corrosion Publication,1994.59-93.