中文摘要：

用ISO/TR10400：2007（E）标准计算套管抗挤强度的KT公式中未考虑套管内壁初始椭圆度及其跳跃性的影响,且提供的套管抗挤毁强度数据主要为M65、T95、H40和非调质N80钢材的,更高钢级和含铬材料的试验数据几乎为零,使得高钢级套管抗挤强度与试验值出现了偏差。通过室内全尺寸试验研究高钢级套管壁厚不均度和内、外椭圆度等参数对套管抗挤强度的影响,并利用试验数据对KT公式进行修正,对比修正前后计算结果与试验值间的误差。研究结果表明：修正后的KT公式具有较高的计算精度,可以满足工程需要;内、外椭圆度对高钢级套管抗挤强度影响具有耦合作用,在制造过程中要严格控制椭圆度及其跳跃性,建议制订相应的套管内壁椭圆度控制规范。

英文摘要：

The Klever-Tamano（KT）equation was obtained in the ISO/TR10400：2007（E）code to calculate the collapse pressure of casing,neglecting inside initial ovality of casing and its jumping.And also,the experimental collapse pressures afforded in ISO/TR10400：2007（E）are mainly M65,T95,H40,non-quenching and tempering N80 casing.The experimental collapse pressures of high-grade and chrome steel casing are zero nearly,which leads to the collapse pressures calculated of high-grade steel casing have an error with the test values.The indoor full scale tests were carried out to get the influence of inequality of the wall thickness and the ovality of casing inner/outer diameter on collapse pressure of high-grade steel casing.The KT equation was improved based on the test data.The calculated results of KT equation and improved KT equation were compared with the test data.The results show that the improved KT equation is more precise than KT equation,satisfying the engineering demands.The ovality of casing inner/outer diameter is coupled.The ovality and its jumping should be controlled strictly in the manufacturing process.The criterion of controlling ovality of casing inner diameter was suggested to establish.