套管钻井中变应力幅载荷下管柱疲劳强度的评估  

Evaluation of Casing String Fatigue Strength under Alternating Stress Amplitude in Casing Drilling

作　　者：赵增新[1] 高德利[1] 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京昌平102249

出　　处：《石油钻探技术》2007年第5期14-17,共4页Petroleum Drilling Techniques

基　　金：教育部"长江学者和创新团队发展计划"创新团队项目(编号:IRT0411);国家自然科学基金重大研究计划项目"山前构造深井轨迹的偏斜规律与控制理论研究"(编号:90410006)资助

摘　　要：套管钻井中,套管柱会承受各种载荷的作用。分对称循环变应力幅载荷和不对称循环变应力幅载荷两种情形,推导了不同钻进参数下考虑变应力幅载荷的套管疲劳强度计算公式,阐明了变应力幅载荷的变化对套管疲劳强度的影响;结合套管钻井的实际给出了算例分析,计算结果显示,在相同条件下采用不对称循环变应力幅载荷模型,计算出的疲劳强度值要比对称循环变应力幅载荷模型的大,表明在实际评估中采用对称循环变应力幅模型计算所得的结果趋于保守,因而具有更高的安全系数。Casing strings stand various alternating stress during casing drilling. Formulas to calculate casing string fatigue strength were developed under different drilling parameters for symmetrical circle and asymmetrical circle alternating stress. Effects of alternating stress amplitude on casing fatigue strength are illustrated. A case analysis was provided with actual conditions in casing drilling. The calculation results indicate that fatigue strength value calculated using asymmetrical circle model was larger than that of using symmetrical model, which indicates that the calculation result using symmetrical model is more conservative and therefore has higher safety coefficient.

关 键 词：套管钻井 载荷 套管强度 疲劳强度 

分 类 号：TE242.9[石油与天然气工程—油气井工程] TE925.2