摘要
针对某油田生产井起出井下管柱作业时发现定位密封处发生穿孔现象,通过宏观分析及测量、理化性能分析、显微组织观察、腐蚀行为分析等方法,对该井定位密封失效原因进行研究。结果表明,短节与油管的化学成分检测结果均满足API SPEC 5CT标准对N80的要求,而定位密封各部位材质不一致,分别为1Cr、13Cr材质,且13Cr材质硬度较高;含砂采出液经油管进入定位密封内部后,受扩径紊流影响,介质集中对定位密封底部形成冲刷,由于13Cr材质耐磨性、耐蚀性均优于1Cr材质,导致1Cr材质冲刷腐蚀严重,进而发生穿孔。建议严格控制管柱各部位材料质量,控制采出液中含砂量及CO_(2)含量,以预防该类失效的再次发生。
In view of the perforation at the positioning seal found in the downhole string operation of a production well in an oil field,the failure causes of the positioning seal of the well are studied by macro analysis and measurement,physical and chemical performance analysis,microstructure observation and corrosion behavior analysis.The results show that the chemical composition test results of nipple and tubing meet the requirements of API SPEC 5CT standard for N80,while the materials of various parts of positioning seal are inconsistent,which are 1Cr and 13Cr respectively,and 13Cr has high hardness.After the sand bearing produced fluid enters the positioning seal from the oil pipe,affected by diameter expansion turbulence,the medium concentration scours the bottom of the positioning seal.Because the wear resistance and corrosion resistance of 13Cr material are better than that of 1Cr material,the erosion corrosion of 1Cr material is serious,and then perforation occurs.It is suggested to strictly control the material quality of each part of the string,and control the sand content and CO_(2) content in the produced fluid,so as to prevent the recurrence of such failure.
作者
王一非
石张泽
张学智
冯电稳
杨中娜
杨阳
WANG Yifei;SHI Zhangze;ZHANG Xuezhi;FENG Dianwen;YANG Zhongna;YANG Yang(Engineering Technology Branch of CNOOC Energy Development Co.,Ltd.,Tianjin 300452,China;Tianjin Branch of China National Offore Oil Co.,Ltd.,Tianjin,300459,China;CNOOC(Tianjin)Pipeline Engineering Technology Co.,Ltd.,Tianjin 300452,China;Tianjin North CNOOC Human Resources Consulting Service Co.,Ltd.,Tianjin 300452,China)
出处
《焊管》
2022年第2期44-48,52,共6页
Welded Pipe and Tube
关键词
井下管柱
定位密封
冲刷腐蚀
失效分析
downhole string
positioning seal
erosion corrosion
failure analysis
