钻柱隔振理论及钻井效率分析

THEORETICAL RESEARCH OF VIBRATION INSULATION FOR DRILLSTRING

应用有限元法建立了钻柱隔振的力学模型，对钻柱进行了纵向振动的动力响应分析和固有频率计算，比较了常规钻柱和隔振钻柱钻头处的位移、井口处的位移以及钻压的变化．钻柱隔振后，其固有频率远高于常规钻井时的激振频率，因此隔振后的钻柱可以避免发生共振现象，提高钻井效率．钻柱隔振理论可以为隔振器的设计和应用提供可靠的理论基础．

The mechanical model of vibration insulation for drillstring is established with the finite element method. The dynamic response of logitudinal vibration is analyzed, and natural frequency is calculated. The displacements of bit and drillstring at well top, variety of WOB of the current drillstring and vibration insulation drillstring are compared. The natural frequencies of current drillstring are smaller than that of vibration insulation drillstring. The resonance of vibration insulated drillstring can be avoided, and the efficiency of drilling can be enhanced. The theoretical research of vibration insulation drillstring is reliable for design and application of vibration insulation sub.