针对文昌13-1/2油田套管设计中采用的13Cr-L-80 和N-80两种钢材偶接的情况,采用挂片失重法研究了两种金属在弱酸性完井液中的电偶腐蚀,筛选了抑制该电偶腐蚀的缓蚀剂,并对其缓蚀性能进行了评价.结果表明,在60 ℃下弱酸性完井液中两种材料偶接时,13Cr-L-80钢腐蚀速度下降,N-80钢的腐蚀速度上升,产生了明显的电偶腐蚀效应.从9种缓蚀剂中筛选出JC-6,在加量1.5%时,13Cr-L-80和N-80偶接、60 ℃时腐蚀速度分别降至0.012和0.165 mm/a；质量比为9∶1的JC-6与PA复配物(代号JCP-6)使偶接钢材腐蚀速度进一步降低,在加量1.5%时,70 ℃时的腐蚀速度分别降至0.013和0.069 mm/a.

Steel 13Cr-L-80 and N-80 was selected as casing materials at Wenchang 13-1/2 oil field.The galvanic corrosion of the two materials in completion fluid was studied by static weight-loss method and the proper inhibitor was selected.The corrosion rate of 13Cr-L-80 increased and that of N-80 decreased at 60℃,indicating the taking place of galvanic corrosion.Corrosion inhibitor JC-6 selected out of 9 commercial chemicals added at dosage 1.5% decreased the corrosion rate of 13Cr-L-80 coupled with N-80 at 60 ℃ to 0.012 and 0.165 mm/a respectively;JC-6 and PA in various combinations could decrease the corrosion rate further and in mass ratio 9∶1 (notated as JCP-6) at dosage of 1.5% could decrease the corrosion rate of the two metals at 70 ℃ to 0.013 and 0.069 mm/a respectively.