1　引言　　在中大斜度井底部钻具组合中正确使用液压推力器可以大幅度降低作业成本 ,成本节约可以从两方面来实现 :一方面在滑动钻进和旋转钻进中机械钻速可以分别提高 3 5 %和 1 5 % ,尽管滑动钻进时机械钻速提高的更加明显 ;另一方面 ,降低了井下工具的故障率 ,特别是随钻测 1 INTRODUCTION The correct use of hydraulic thrusters in the middle-large deviated well bottom drilling assembly can greatly reduce the operating cost. The cost saving can be achieved in two aspects. On the one hand, the ROP can be separately used in sliding drilling and rotary drilling By 35% and 15% respectively, even though the ROP increased more significantly with sliding drilling; on the other hand, the failure rate of downhole tools was reduced, especially with drilling