基于驱动装置的钻孔重入系统偏移控制分析

Analysis of deviation control for drilling re⁃entry system based on driving device

深海钻探中,无隔水管钻进工艺不受隔水管长度限制,能够在所有水深范围内实施钻探作业,但随水深增加钻具重入钻孔难度极大,钻孔重入系统对于无隔水管钻探尤为重要。深海钻探工况十分复杂,受海浪洋流等各种因素作用,钻柱近似为柔性杆件,在不使用水下机器人(ROV)的情况下,常规钻柱重入作业耗时很长,成功率低,即使通过上部移船的方式移动钻柱受到海况因素制约也很难实现。因此,研究钻孔重入系统偏移控制技术对于深海钻探大有裨益。通过分析自由状态下钻柱重入钻孔的姿态及效率,使用带有驱动装置的钻孔重入系统,针对性平衡钻柱底部的水动力作用,可有效保证重入钻孔时底部钻具的稳定性,最大程度缩短重入钻孔时间,减少深海无隔水管钻探工艺成本。

In deep‑sea drilling,the drilling process without a riser is not limited by the length of the riser,and can carry out drilling operations within all water depths.However,as the water depth increases,the difficulty of drilling tools re‑entering the borehole is extremely high,and the drilling re‑entry system is particularly important for drilling without a riser.The working conditions of deep‑sea drilling are very complex,and due to various factors such as ocean waves and currents,the drill string is approximately a flexible rod.Without the use of ROV,the conventional drill string re‑entering operation takes a long time and has a low success rate.Even if the drill string is moved by the upper moving ship due to sea conditions,it is difficult to achieve.Therefore,studying the deviation control technology of the drilling re‑entry system is of great benefit for deep‑sea drilling.By analyzing the posture and efficiency of the drill string re‑entering the borehole in a free state,a drilling re‑entry system with a driving device is used to balance the hydrodynamic effect at the bottom of the drill string,effectively ensuring the stability of the bottom drilling tool during re‑entering the borehole,minimizing the re‑entery drilling time,and reducing the cost of the deep‑sea non riser drilling process.