80-3Cr油管钢在CO_(2)驱环境下的性能研究与应用

Performance Research and Application of 80-3Cr Tubing Steel in CO_(2) Flooding Environment

针对CO_(2)驱高CO_(2)分压、高H_(2)S分压、低温井筒环境造成N80、P110管柱失效的问题,开展了80-3Cr、N80、P110三种管材的耐CO_(2)腐蚀、抗H_(2)S应力腐蚀开裂、耐低温冷脆对比评价试验。结果表明,不同CO_(2)工况条件下,N80、P110、80-3Cr油管在添加缓蚀剂情况下的腐蚀速率分别为0.0549 mm/a、0.0645 mm/a、0.0333 mm/a;80-3Cr油管的腐蚀速率明显低于N80、P110油管;80-3Cr油管在不同H_(2)S环境下均未出现应力腐蚀开裂,具有较好的抗H_(2)S应力腐蚀性能;在-20℃的低温环境下,N80和P110油管冲击功分别只有80-3Cr油管的62.6%和23.2%;80-3Cr油管在CO_(2)驱油现场应用后,管柱失效率从2019年的20%下降到0,取得显著效果。

Aiming at the problems of N80 and P110 string failure caused by high CO_(2)partial pressure,high H_(2)S partial pressure and low temperature wellbore environment in CO_(2)flooding,the comparative evaluation tests of CO_(2)corrosion resistance,H_(2)S stress corrosion cracking resistance and low temperature cold brittleness resistance of 80-3Cr,N80 and P110 tubings were carried out.The results show that the corrosion rates of N80,P110 and 80-3Cr tubing with corrosion inhibitor are 0.0549 mm/a,0.0645 mm/a and 0.0333 mm/a,respectively,under different CO_(2)conditions.The corrosion rate of 80-3Cr tubing is significantly lower than that of N80 and P110.80-3Cr tubing have no crack under different H_(2)S stress corrosion cracking conditions,and all of them have good H_(2)S stress corrosion resistance.At-20℃,the impact power of N80 and P110 tubing is only 62.6%and 23.2%of 80-3Cr tubing respectively.After the application of 80-3Cr tubing steel in the field of CO_(2)flooding,the string failure rate decreased from 20%in 2019 to 0,which has achieved remarkable results.