水力加压器研制及应用

在大位移井、小井眼井和水平井中靠钻铤重量向钻头施加钻压非常困难,为解决这一难题,研制出一种利用钻井液来提供钻压的水力加压器,该水力加压器有2种类型,一种是单行程水力加压器,这种加压器只能依靠改变钻井液排量来改变钻压;另一种是双行程水力加压器,这种加压器入井后可通过控制活塞行程来控制钻压。介绍了水力加压器的原理、结构及在硬地层、夹层、深井小井眼和开窗侧钻井中的应用效果。结果表明,使用水力加压器可提供平稳的钻压,减轻钻具的轴向振动,减少钻具的疲劳失效,延长钻头的使用寿命,提高机械钻速。

Development and Application of the Thruster

With the development of the petroleum industry, more and more re entry wells, horizontal wells, slim hole and Extended Reach Well have appeared. For these wells, it is difficult for drill collars to provide WOB because of the high hole angle or big torque/drag. As a result, how to exert WOB is a problem concerned by drilling engineers. Hence two types of thruster which provide WOB by the drilling fluid have been developed. One can provide one kind of WOB named single travel thruster and the other can provide two kinds of WOB named double travel thruster. They have been used for hard formation, intermediate layer, re entry and deep slim hole drilling in Tarim, Sichuan and Zhongyuan oil field etc.. Using the thrusters, the WOB is smoothly applied on the bit, the bit made axial vibration of the drill string above the thruster is reduced, the fatigue failure of the drill string and drill collar is decreased, the service life of the bit can be longer, and the ROP can be increased.