钻柱轴向振动仿真与井底状态监测方法探讨

Computer simulation of drillstring axial vibration and online monitoring of bottom hole condition.

在钻柱轴向振动的研究中 ,为了弥补先前的变量分离法和有限单元法存在的不足 ,提出了广义传递矩阵法。根据钻柱结构、受力和运动特性 ,建立了适合任意钻柱组合 ,且能真实反映钻柱系统的轴向振动的计算机仿真模型。引入描述钻柱轴向振动特性的广义状态向量 ,可简化复杂的工程计算问题。针对不同的测量方法 ,可仿真钻柱不同截面与不同功用的振动量。实现的两种仿真方案中 ,方案 (1)可用来优选钻头、优化设计钻具组合和优选钻井参数 ;方案 (2 )可用来随钻监测井底工况。

Based on the characteristics of axial vibration of the drillstring,and by introducing the generalized state vector and the generalized transfer matrix method,a computer simulation model for arbitrary drillstring assembly is set up,which can reveal actual axial vibration of the drillstring assembly.By means of the axial vibration information processing and analysis of downhole working conditions and rock property,online monitoring of bottom hole conditions can be realized.