套管强度余量在油气井固井中的应用

APPLICATION OF CASING STRENGTH MARGIN TO OIL AND GAS WELL CEMENTING

套管强度性能受多种因素的影响,如何确定套管强度余量及其大小,是一个难题。通过对近几年国产套管实物试验数据的统计,采用与API套管强度额定值相比较的方法,对套管强度余量的主要影响因素钢级和壁厚进行了分析。统计检验分析表明,国内主要套管生产厂的API套管强度性能趋于稳定达到较高水平,存在高于API额定值的强度余量。现场应用表明,采用套管强度余量设计管柱时,应对套管进行全面的实物试验评价。

Since casing strength performance can be influenced by many factors,it is hard to confirm casing strength margin and its value.As a result,based on the statistics of experimental data of domestically-made casings,compared with nominal value of API casing strength,the main influencing factors on casing strength margin such as steel grade and wall thickness are analyzed.The statistical examination shows that strength performance of API casing from major domestic casing producers reaches stable and higher level and strength margin is a little higher than API nominal value.The field application shows that a comprehensive evaluation should be done on casing before designing drill string by using casing strength margin whose study provides references for making use of strength margin when designing drill string economically and reliably.