钻柱动力学研究及应用进展

STUDY AND APPLICATION OF DRILLING STRING DYNAMICS

石油钻井钻柱是石油工业中用量大、质量要求高的管材,处在充满钻井液的狭长井眼里工作,受力情况非常复杂。每年国内外都会发生大量钻柱失效事故,造成重大经济损失。在钻柱失效调研分析的基础上,阐明了钻柱失效的主要原因,指出了钻柱动力学研究的重要性,详述了国内外钻柱动力学研究的历史和最新进展,介绍了钻柱动力学研究的应用现状,分析了现存模型的优缺点和国内外研究的差距,总结了钻柱动力学的研究方法,强调了钻柱动力学研究急需解决的核心技术问题。现有钻具材质及结构条件下,减少钻柱疲劳破坏的最有效途径是根据钻柱的动态应力特征,优化钻柱结构和工作参数,使钻柱尽可能在低动态应力水平下工作。

Drill string that consists of drilling pipes with large quantity and high quality works at narrow and long borehole filled by drilling fluid. Its force-summing situation is very complicated. Many accidents caused by drilling string failure happen at home and abroad every year, which lead to serious economic loss. Based on the study of drilling string failure, it is described the main reasons of drilling string failure and it is explained the importance of the study on drilling string dynamics. It is stated in detail the history and the latest progress of the study on drilling string dynamics at home and abroad. It is introduced the application status of the study on drilling string dynamics. It is analyzed both advantages and disadvantages of the existing models and the gap of the study between China and other countries and it is also summed up the study method of drilling string dynamics. It is especially focused on the key technical problems to be solved for the study on drilling string dynamics. Under the current conditions of the existing material quality and structure of drilling strings, the effective way to reduce the fatigue failure of drill strings is to optimize the structure and working parameters of drilling strings by the dynamic stress features of drilling strings to make drilling strings working at low dynamic stress level as much as possible.