中文摘要：

通过对高温条件下高钢级套管进行室内试验,得到了Q125、V140和V150套管屈服和抗拉强度值,并引入强度折减系数,回归出高温条件下相应强度折减系数计算公式.为了满足油田实际设计需要,给出了高钢级套管在150℃和200℃下的统一强度折减系数推荐值,并被中国石油天然气行业标准采纳,推广应用于高温下套管柱设计.根据试验结果及回归公式,对中国西部某深井套管柱进行了设计校核和安全评价.计算结果表明：本文试验结果和回归公式具有很好的通用性,可以满足现场工程需求;高钢级套管屈服强度和抗拉强度随温度增加而显著降低,且屈服强度降低幅度要大于抗拉强度,建议在高温井套管柱设计过程中要考虑温度对管材性能降低的影响.

英文摘要：

The yield strength and tensile strength of high-grade steel casings such as Q125,V140 and V150 were obtained by indoor experiments under high temperature conditions.The strength reduction factor was introduced and its equation applicable for the high-grade steel casings at high temperature was regressed from the experimental data.The strength reduction factors at 150 ℃ and 200 ℃ were given for convenient applications in oilfields,adopted by Chinese Petroleum and Natural Gas Industry Standards and applied to the design of high temperature casing strings.Design verification and safety evaluation of deep-well casing strings in western China based on the experimental results and the regression formulas show that the experimental data have good versatility to meet the requirements of field casing design.The yield strength and tensile strength of the high-grade steel casings decreases greatly with increasing temperature,and the decrease rate of yield strength is greater than that of tensile strength.It is suggested that the influence of temperature on the material properties of the high-grade steel casings should be considered during the design of high-temperature well casing strings.