钻柱横向振动对套管鞋及井下安全的影响

Effect on Casing Shoe and Downhole Safety by Horizontal Vibration of Drilling String

本文应用钻柱横向自由振动的振型函数关系,分析钻柱发生横向自由振动的规律及其特点,并着重研究发生在套管鞋处的横向自由共振对套管鞋及附近水泥环所产生的危害及影响。通过对两口井卡钻事故的分析,说明了认识钻柱横向振动的重要性以及避开共振转速的必要性,并且就如何保护套管鞋、防止水泥掉块、保证井下安全,提出了作者自己的认识和看法。

This paper uses the function relationship of vibration forms of the horizontal free vibration of drilling string to analyze the law and characteristics of the horizontal free vibration of the dulling string, and studies emphatically the harm and effect of the casing shoe and its surroundings of cement annulus because of the horizontal free vibration at the casing shoe. By the analysis of the two wells' sticking accidents, the importance to know the horizontal vibratiou is set out and the necessity to avoid the resonant ROP (rate of penetration) is emphasized. The author's comments and points of view are presented on the protection of the casing shoe, prevention of cement falling, and the guarantee of the dowuhole safety.