对于同一口油井来说,腐蚀介质基本一致,但是井下油井管各部位的腐蚀差异却较大,这主要是环境因素造成的.本文讨论环境因素引起的杂散电流腐蚀、缝隙腐蚀、电偶腐蚀和应力腐蚀.这些腐蚀现象在油气田开发过程普遍存在.入井管具较多,因材质存在一定的差异,电位差较大的局部区域出现较严重的电偶腐蚀.在其连接处可能发生缝隙腐蚀,钻杆加厚过渡带的残余应力将诱发应力腐蚀.希望本文的讨论为油田开发的相关设计和决策提供一定的参考依据.

The corrosion degree of different downhole pipes varies greatly in the same well although different downhole pipes are in a similar corrosion medium.This results from the environmental factors.The present paper is mainly discusses stray current corrosion,crevice corrosion,galvanic corrosion and stress corrosion.These corrosion phenomena often occur during oil/gas exploitation.There are many different pipes in one downhole well.Severe galvanic corrosion will occur if potential difference in local areas is large.Crevice corrosion occurs in the connection parts.The residual stress may induce stress corrosion,such as in thickened transition zone of drill pipe.