酸性气田连续油管作业防硫缓蚀剂研究与应用

针对酸性气田连续油管作业,在高温高压强酸性环境下,连续油管不可避免的受到湿H2S腐蚀,导致连续油管性能退化,引起穿孔、氢脆及断裂等现象,连续油管使用寿命明显缩短。通过实验评价,研选出了咪唑啉类A-283防腐缓蚀剂作为连续油管在酸性气田环境下作业用缓蚀剂,在100℃、70 MPa、5000 mm/s的17.5%H2S气体速率中反应24 h缓蚀率95.4%,最佳加入浓度是5%,在酸性环境中结构性能稳定,无毒、无污染,缓蚀时间长、受腐蚀次数多。在酸性气田D402井现场应用中,连续油管内外表面喷涂预膜A-283缓蚀剂处理液后,缓蚀率达到95.6%,防硫缓蚀效果显著。

Study and application of anti-sulfur corrosion inhibitor for coiled tubing in sour gasfield

Coiled tubing operation in acid gasfield,coiled tubing is inevitably subject to wet H2S corrosion under high temperature,high pressure and strong acid environment,which leads to performance deterioration of coiled tubing.It causes perforation,hydrogen embrittlement and fracture,and the service life of coiled tubing is significantly shortened.Through experimental evaluation,imidazoline A-283 corrosion inhibitor was selected as corrosion inhibitor for coiled tubing operation in sour gasfield.At the gas rate of 17.5%H2S at 100℃,70 MPa and 5000 mm/s,the inhibition rate was 95.4%in the 24 h response,and the optimum concentration is 5%.In the acid environment,the structure performance is stable,non-toxic,no pollution,corrosion inhibition time is long,withstand corrosion more times.Field application in well D402 of sour gasfield,the corrosion inhibition rate reaches 95.6%after coating A-283 series corrosion inhibitors on the inner and outer surfaces of coiled tubing,anti-sulfur corrosion inhibition effect is remarkable.