关键词: 钻柱 , 竖直 , BHA系统 , 有限元法

Abstract: In the oil drilling process,the motions of the drill string is very complicated process,which exists longitudinal,horizontal and torsional vibrations and random impacts and rubs between the well wall and drillstring.The non-linear dynamics finite element model of the bottom hole assembly (BHA) system was established with considering random impacts and rubs between the well wall and drillstring,drill bit and the rock.The transient vertical-horizontal-torsional coupling vibrations of the BHA system were studied with finite element method (FEM).The rules of the vibration motions and mechanical properties in the BHA were found out.The calculated results provide the references to oil drill string design and optimization of the system.

Key words: Drillstring , Vertical wells , Bottom hole assembly(BHA) , Finite element method