三维井眼全井钻柱系统动力学模型研究

依据Hamilton原理,利用有限元法建立了综合考虑钻柱纵向横向扭转耦合振动、钻柱与井壁的碰撞及摩擦、钻井液对钻柱的黏滞阻尼、钻柱内钻井液对运动钻柱的弯曲效应、环空钻井液对运动钻柱的压差效应、地层压差效应、屈曲对摩阻的增益、钻头与岩石相互作用等因素的三维井眼全井钻柱系统动力学模型。研究了具有不确定性和动态边界的大型非线性系统的求解方法,开发了钻柱系统动力学特性仿真软件。该软件可以计算任意钻井参数、钻具组合、钻井液参数及地层参数下任意钻柱单元的动力学特性参数(包括位移、速度、加速度、载荷等)。

Research on dynamics model of full hole drilling-string system with three-dimensional trajectory

According to Hamilton Principle and finite element method, the dynamics model for full hole drilling-string system with three-dimensional trajectory was established by synthetically considering some factors. The factors were longitudinal vibration, transverse vibration and torsion vibration of drilling string, collision between drilling string and wall of well, friction between wall of well and drilling string, sticky damping between slurry and drilling string, bending effect of moved drilling string caused by slurry in drilling string, differential pressure effect of stratum, attached effect of resistance caused by buckling and interaction between drilling bit and rock. The resolution method for a large nonlinear system with uncertainty, dynamic and quasi-stochastic boundaries was investigated. Emulation software for emulating the dynamics characteristic parameters, including displacement, velocity, acceleration and load of drilling string element, was developed. It can be run under freewill drilling parameters, drilling tool, drilling fluid and stratum.