井下液力推进器在大斜度定向井中的应用

Application of downhole hydrodynamic propulsor on drilling high angle deviated holes.

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。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。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。１９９５～１９９８年井下液力推进器在大港油田等地区不同区块２０余口井上施工的实践证明，使用这种推进器不但可以提高机械钻速，而且减轻了钻头和钻杆的振动，进而延长了钻头寿命。但在井型的适应范围和小曲率造斜井的施工等方面，推进器的使用还存在一定的局限性，有待进一步完善和发展。

In drilling high angle deviated holes, friction is the main factor affecting the effective WOB. Application of downhole hydrodynamic propulsors solves the problem of exerting WOB, and are helpful to enhancing penetration rate. 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. Field operation shows that, by using the hydrodynamic propulsor, not only the penetration rate is increased, the vibration of the bit and drill stem is reduced as well, thereby the service life of the bit is extended. The downhole hydrodynamic propulsor has yet to be improved since it has some limitations in operation.