关键词: 钻柱, 岩石, 钻头, 动力学, 扭振, 模型

Abstract: Based on the interaction of bit and formation,the force from the rock and bit is used for the boundary condition of the end of the drill string.As simplified by the elastic bar theory and FE method,a torsional vibration model for the drill string simulates the bit/formation interaction and elastic deformation of the drill string is established.The torsional model is solved by numerical method by considering the boundary condition and initial condition.The theoretical work in this paper is the basis for the dynamic behavior and kinetics of drilling string and rock bit and for well orbit control early failure prevention.

Key words: string, rock, bit, dynamics, torsional vibration, model