【摘要】 为防止井眼偏斜，降低直井的纠斜率，提高钻井速度和井身质量． 设计了一种新型偏心防斜钻具组合， 建立了钻具模型，利用有限元法对模型进行了求解，并与标准钻具进行了对比． 利用偏心钻具在旋转过程中的离心力和偏心短钻铤的偏重带的支撑作用，减小了钻头轴线倾角，从而减少了井斜． 通过三种钻具的对比分析，说明偏心钻具具有较好的防斜效果． 现场应用表明：采用偏心钻具，纠斜率由８ ．９ ％ 降至２ ．８ ％ ，平均机械钻速由２６ ．３０ ｍｈ 提高到３４ ．９６ ｍｈ ．更多还原

【Abstract】 A new eccentric assembly is presented in this paper, which can effectively prevent well inclination, reduce the rectifying rate of vertical well and improve drilling speed and well quality. By taking advantage of rotating centrifugal force and the supporting effect of eccentric short drill collar, we cut off the axis inclination of bit, and avoid well inclination. By contrasting analysis of three types of bottom hole assemblies, the eccentric assembly proves to be the best in preventing well inclination. Meanwhile, field application shows that, by using the eccentric assembly, the rectifying rate is cut down from 8.9% to 2.8%, while the average drilling speed increases from 26.3 m/h to 34.96 m/h, so drilling speed and well quality are greatly improved, thus saving the drilling cost.更多还原