深水无隔水管钻井全井钻柱纵-横-扭耦合非线性振动模型研究

Longitudinal-transverse-torsional coupled nonlinear vibration model ofdrill string in deepwater riser-free drilling

无隔水管钻井是一项极具发展前景的深水钻井技术。针对深水无隔水管钻井缺乏有效的动力学分析模型的实际,通过能量法、微元法结合哈密顿原理,建立了考虑钻井船位移、风海流、潮流、波浪载荷、井壁接触、钻头-岩石互作用、海水段-地层段互作用的深水无隔水管钻井全井钻柱纵-横-扭耦合非线性振动模型;通过拉格朗日和三次埃尔米特函数离散控制方程,采用Newmark-β对模型进行数值求解;采用现有海洋立管模拟试验数据、Moharrami扭转振动模型结果及Kyllingstad现场测试数据,对模型进行了详细对比验证。结果表明,该模型精度较好,可用于深水无隔水管钻柱的耦合振动分析。

Riser-free drilling is a promising deepwater drilling technology.Here,aiming at the fact of no effective dynamic analysis model for deepwater riser-free drilling,a longitudinal-transverse-torsional coupled nonlinear vibration model of drill string in deep-water riser-free drilling was established by combining the energy method,the differential element method and Hamilton principle considering displacement of drilling vessel,wind current,tidal current,wave load,wall contact,bit-rock interaction,and interaction between seawater segment and stratum segment.The governing dynamic equation was discretized with Lagrange and cubic Hermite functions,and Newmark-βmethod was adopted to solve the model numerically.The detailed contrastive verification was performed for the proposed model by adopting existing marine riser simulated test data,results of Moharrami torsional vibration model and Kyllingstad onsite test data.The results showed that the proposed model has better accuracy;it can be used for coupled vibration analysis of deepwater riser-free drill string.