NONLINEAER STUDY ON DYNAMIC ACTION OF INTEGRATED DRILL STRING-WELL ROCK SYSTEM

ZHU Caichao¹  FENG Daihui¹  LU Bo¹  YANG Yingxin²

(1. State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing 400030;
2. State Key Laboratory of Oil Drilling, Southwest Petroleum Institute, Nanchong 637001 )

Abstract: In the process of drilling well, the kinematics of drill string is quite complicated. The drill string not only vibrates in longitudinal, transverse and torsional direction, but also random impacts and contacts well wall. Considering random load of drill bit and rock, contact impact of drill string and well wall, nonlinear dynamic model of drill string system coupling longitudinal, transverse and torsional vibration is set up, numerical method of parameter of high nonlinear dynamic model is studied, kinematics law, mechanical property of drill string are discussed. This can establish foundation for nonlinear dynamic theory of drill string system coupling vibration in the actual work condition, and has important theory significance and academic value.

Key words: Drill string Dynamic Finite element Contact impact Couple analysis

CLC No: TD421

国家自然科学基金(90410004)、新世纪优秀人才计划(NCET-05-0766)和重庆市科委自然科学基金计划(2006BB3208)资助项目. Received 20060801, received in revised form 20070112