关键词: 套管钻井, 套管柱, 剩余强度, 疲劳可靠度, 磨损量, CAE仿真技术

Abstract: The mechanics in the process of casing drilling were analyzed using the CAE stimulation and tests of fatigue reliability,including the force acted on the casing with different diameter-thickness ratio,residual intensity of worn casing,vibration modal and fatigue reliability of the casing string.The study results showed that the Mises stress on the casing had a proportional relation with the diameter-thickness ratio,and the critical instability load of casing had a reverse proportion with the diameter-thickness ratio.For the uniform wear of casing,the longer of the wear length of casing led to the bigger residual intensity and resistance to distortion,which finally reached a limit value.For the non-uniform wear of casing,the residual intensity had an exponential relation with the wear length.The residual intensities both the uniform wear and non-uniform wear of casings have the reverse proportions with the abrasion depth on casings.The external diameter of casing had the more influence on lateral vibration inherent frequency than the diameter-thickness ratio.The length of casing string controlled the lateral vibration inherent frequency.The reliability tests both the axial fatigue and the biaxial fatigue of casing strings were designed by means of examination and numerical simulation,and the P-S-N curves were obtained.

Key words: casing drilling, casing string, residual intensity, fatigue reliability, wear rate, CAE simulation