In drilling high angle deviated holes , friction is the main factor affecting the effective wob 在大斜度定向井钻井过程中，摩擦阻力是影响有效钻压的主要因素。
2.
Application of downhole hydrodynamic propulsors solves the problem of exerting wob , and are helpful to enhancing penetration rate 井下液力推进器的应用在一定程度上解决了钻压的施加问题，有利于提高钻进速度。
3.
The hydrodynamic propulsor takes drill fluid as power source , with the aid of the axial load produced by the pressure drop of the bit nozzle , makes the axial force act on the bit to produce wob , making up for the insufficient wob , ensuring the bit feeding smoothly and improving the penetration rate 这种推进器以钻井液为动力源，借助钻头喷嘴压降产生的轴向载荷，使轴向力直接作用于钻头产生钻压，弥补有效钻压不足，保证钻头平稳钻进，提高机械钻速。
