CO_2生产井的腐蚀机理及预防

CORROSION MECHANISM AND PREVENTIVE MEASURE ABOUT CARBON DIOXIDE WELL

在ＣＯ２气井生产中的ＣＯ２气体，溶解于水形成碳酸后引起金属的电化学腐蚀，使气井生产的中心管和套管严重锈蚀，如不及时采取检修更换管串等措施，将导致气井停产甚至报废。探讨了ＣＯ２对井下管串的腐蚀机理及影响因素，提出主要预防措施为：定期检查井内管串、优化气井的井身结构、优选抗腐蚀的油管和套管、加注缓蚀剂、采用表面涂层保护等工艺。苏北ＣＯ２生产井采取相关的预防措施后效果显著，气井正常采气周期长达 １０年以上。

When production CO2 dissolution in water in the well, it can production carbonic acid who may cause electrochemical corrosion of metal,which make casing and production center tube corrosion severity. This would cause well off production or out of use if not examined and repaired in time. The corrosion mechanism and affect factor were discussed through three corrosion types example analysis. So the main preventive measures were put forward: inspect wellbore pipe string timing; optimize casing program; optimize corrosion resistance casing and tubing; add corrosion inhibitor; etc. After Using the system preventive measures, the gas production well in Subei obtained notability effect,the gas production period over ten years.