Abstract: The yield strength of the casing directly affects the anti-extrusion performance of the casing. During the processing of casing hole, metal phase transformation may happen in the material near the hole. Thus the yield strength is no longer uniform in the whole casing, which affects the crushing strength of the casing. Taking the P110 casing as an example, the crushing strength of the complete casing and the machined hole casing under the same working conditions were compared. And as a reference group, the influence of the area of the phase transition region and the yield strength of the phase transition region on the crushing strength of the machined hole casing were analyzed. The results showed that the machined hole changed the yield strength of the material, which affected the anti-extrusion performance of the casing. When the yield strength of the metal phase transition region reduced, the extrusion strength of the machined hole reduced, and when the yield strength of the metal phase transition region increased, the extrusion strength of the machined hole increased. And the effect of the phase transition region of the machined hole casing on the extrusion strength of the machined hole casing was gradually weakened with the increase of the yield strength in the phase transition region.

Key words: yield strength, machined hole casing, metal phase transformation, anti-extrusion performance, phase transition region

摘要： 套管屈服强度直接影响套管抗挤压性能，套管在加工孔过程中可能诱发孔眼附近材料发生金属相变，导致套管屈服强度不再均匀分布，进而影响套管抗挤压强度。在相同工况下，对比了P110完整套管和机加工孔套管的抗挤压强度，以此为参照组分析了相变区域面积和相变区域屈服强度对机加工孔套管抗挤压强度的影响。结果表明，机加工孔会改变材料屈服强度，进而影响套管抗挤压性能。随金属相变区域屈服强度减小，机加工孔套管抗挤压强度减弱；当金属相变区域屈服强度增大时，机加工孔套管抗挤压强度增强。且机加工孔套管相变区域面积对机加工孔套管抗挤压强度的影响随相变区域屈服强度增加而逐渐削弱。

关键词: 屈服强度, 机加工孔套管, 金属相变, 抗挤压强度, 相变区域