关键词: 定向井, 有杆泵, 抽油系统, 有限元法

Abstract: The fault occurring probability of sucker pumping system of directional wells is higher than that of straight wells.The fault diagnosis technique for sucker-rod pumping system of straight wells can not be applied to that of directional wells for their 3-D well curve,or it will result in a big error.Existing mechanical analysis about directional well systems only consider 1-D vertical vibrations of sucker rod,fluid,and tube,or consider 3-D vibration of sucker rod only.This paper presents a FEM and FFM method to analyze 3-D couple vibrations of rod,fluid and tube,the three systems of directional well.The result calculated with this method gives precise pump displacement-load plots.The fault diagnosis about pumping system according to these plots has achieved good results in pump checking.

Key words: directional well, sucker-rod pumping system, finite element method