雅克拉凝析气井井下流动短节断裂失效分析

雅克拉凝析气井井下流动短节多次发生断裂事件,造成高额的修井维护费用。为提高井下流动短节在服役环境使用的安全性,有必要弄清其断裂失效原因,为优选材质提供依据。通过对YK8和YK14H井井下流动断裂短节取样,利用金相显微镜、扫描电镜、荧光光谱仪、X衍射仪对井下流动短节腐蚀试样进行表面形貌、腐蚀产物组成分析,研究井下流动短节断裂失效原因,结论为材质硬度超标和在井流物H2S和CO2腐蚀环境下的腐蚀。优选材质是减少流动短节断裂最有效的方法。

Analysis on Fracture and Failure of Downhole Flow Nipples in Condensate Gas Wells of Yakela Gas Field

More than once fractures of downhole flow nipples in condensate gas wells of Yakela Gas Field have resulted in very high well repair and maintenance cost.In order to reduce such fractures and strengthen the safety,it is necessary to ascertain the reasons for fracture failures and provide basis for optimization of materials.Sampled are some fractured flow nipples in well YK8 and YK14H,used are metallographic microscopes,scanning electron microscopes,fluorescence spectrometers and X-ray diffractometers to detect and research surface morphologies of fractured flow nipple samples and their corrosion product compositions and analyze the reasons for fracture failures of such nipples.The analysis results show that material hardness exceeds requirements in relative standards and downhole CO2 and H2S result in such corrosion.It can be such concluded that optimization of materials is the most effective way for reducing fractures of downhole flow nipples.