一种油田深井用新型耐高温锌合金牺牲阳极

摘要

为解决某油田4 000 m深井TP110-3Cr套管外腐蚀问题,研制了一种新型耐高温锌合金牺牲阳极.采用电化学技术对阳极材料进行了极化曲线和电流效率测试.结果表明:在80℃时,阳极极化曲线较平缓,开路电位较负,无高温“逆转”现象,电流效率大于80％,腐蚀均匀,腐蚀产物易脱落.在模拟某油田地层水条件下,评估了新型阳极的高温防腐蚀性能.结果表明:新型锌合金牺牲阳极在125℃以下,可有效保护套管;在130℃时,阳极发生断裂失效,无法继续使用.%To control the external corrosion of TP110-3Cr casing of a 4 000 m depth well in an oilfield,a new-type zinc alloy sacrificial anode at elevated temperature was developed.Measurements of polarization curves and current efficiency of the anode show that at 80 ℃,polarization curve was relatively flat,open circuit potential quite negative and no potential reversal phenomenon was observed,the current efficiency reached 80％,its corrosion morphology was uniform and corrosion products easily falled off.In simulated water of the oilfield site,the corrosion protection performance of the new-type sacrificial anode was evaluated at elevated temperature.It can be concluded that the new anode can protect the casing material efficiently below 125 ℃,while at 130 ℃cracking phenomenon might appear and the anode can not be used.