对API标准中关于套管水压试验压力、套管内屈服压力和套管内压性能试验等内容进行了解析, 认为API规定的水压试验主要是检查套管管体是否渗漏, 并非检查套管接头密封性能。对套管内压至失效试验结果进行了分析, 认为各项参数符合API标准的套管内屈服压力远远高于API TR 5C3-2008的内屈服压力规定值, 应当按照API TR 5C3-2008规定的内屈服压力而不是静水压试验压力进行套管柱设计。通过对套管内屈服压力计算公式进行解析, 对套管接箍失效事故进行调查研究, 认为对套管接箍外壁进行机械加工有利于防止深井和超深井发生接箍失效事故。建议用户对套管上扣所用螺纹脂、水压试验压力和稳压时间、套管内屈服强度等主要性能进行严格要求。

The API standards of casing hydrostatic testing pressure, casing internal yield pressure and resisting inner pressure performance were analyzed, and it was considered that the purpose of hydrostatic pressure test specified by API was mainly to inspect whether or not the casing pipe body leaked, but not to inspect the connection seal performance. Through the analysis on the internal pressure-to-failure test results, it was found that the internal yield pressure of the casings was much higher than that specified by API TR 5C3-2008 as long as the various parameters of the casings were in accordance with API specification. Thus the casings should be designed in accordance with casing internal yield pressure specified by API TR 5C3-2008, instead of the hydrostatic pressure. Through the analysis on the calculation formula of casing internal yield pressure and the investigation on the casing coupling accidents, it was deduced that casing couplings of deep well and ultra deep well could be prevented from failure by the machining on the casing coupling outside surface. It is suggested that the thread compounds, hydrostatic test pressure and hold time, and casing internal yield pressure etc. should be required strictly by users.