Abstract Suppressing torsional vibration of drill-string has great safety and economic importance to drilling process. Note that most existing control methods only measure surface information, their performance are limited, especially for a long drill-string. In this paper, an advanced control system is developed to mitigate torsional vibration of drill-string, using a measurement-while-drilling (MWD) communication tool to collect downhole information. The drill-string is described by a lumped parameter model to include full torsional flexibility modes with less computational complexity. A state observer and a filter are combined to estimate an equivalent control torque to cope with uncertain bit–rock interaction. Considering that the communication and power resources are quite precious for MWD, the downhole state is periodically sampled and an event-triggered mechanism is devised to pick out only some key sampled data for transmission to the surface. Using both the surface continuous measurement and the discrete MWD data with transmission delays, the closed loop of the drill-string and the control system is modeled as a nonlinear time-delay system, based on which sufficient conditions are derived for stability analysis and calculation of gain matrices. A numerical case study is carried out to verify the effectiveness of the approach.

中文翻译：

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一种基于随钻测量数据的事件触发钻柱系统扭转振动控制方法

摘要 抑制钻柱扭振对钻井过程的安全性和经济性具有重要意义。请注意，现有的大多数控制方法仅测量表面信息，其性能有限，特别是对于长钻柱。在本文中，开发了一种先进的控制系统来减轻钻柱的扭转振动，使用随钻测量 (MWD) 通信工具收集井下信息。钻柱由集总参数模型描述，以包括计算复杂度较低的全扭转柔性模式。结合状态观测器和滤波器来估计等效控制转矩，以应对不确定的钻头-岩石相互作用。考虑到通信和电力资源对于 MWD 来说是非常宝贵的，井下状态被定期采样，并设计了一个事件触发机制来仅挑选一些关键的采样数据以传输到地面。利用地面连续测量和具有传输延迟的离散MWD数据，将钻柱和控制系统的闭环建模为非线性时滞系统，在此基础上推导出足够的条件进行稳定性分析和计算。增益矩阵。进行数值案例研究以验证该方法的有效性。在此基础上推导出稳定性分析和增益矩阵计算的充分条件。进行数值案例研究以验证该方法的有效性。在此基础上推导出稳定性分析和增益矩阵计算的充分条件。进行数值案例研究以验证该方法的有效性。