【摘要】 水射流钻径向孔用喷管的前端牵引钻进方式存在自牵引力小,限制了喷管长距离钻进的问题;地面下放钻进方式又存在力传递情况复杂,下放速度波动大,地面难以实现井下钻进速度精确控制等问题。鉴于此,研究了水射流钻径向孔用步进式钻进系统。该系统通过低速钻进控制器实现喷管的低速钻进,通过步进式锚定送进机构保证喷管持续钻进。试验结果表明:该系统可实现喷管在地层中低速(0.5～3.0 mm/s)、大推力(2 k N)、长距离(≥10 m)钻进;该系统的钻进速度与射流破岩速度(0.3～5.0 mm/s)一致,能够使喷管与岩石之间保持较稳定的喷射距离,有利于喷管长距离钻进;在埋藏浅、岩石软、孔隙度大、围压小和温度高的情况下,破岩钻进效率高,反之则较低。研究结果可为喷射钻进技术的进一步研究应用提供一定的参考。更多还原

【Abstract】 The low traction force of the front-end nozzle for water jet radial drilling limits the drilling distance.The ground run drilling method has complex force transmission,large run-in-hole fluctuation,and has difficulty in the ground precise control of downhole drilling speed. In view of this,a step drilling system for water jet radial drilling is studied. The system realizes the low-speed drilling of the nozzle through the low-speed drilling controller,and ensures the continuous drilling of the nozzle through the step anchor feeding mechanism. The test results show that the system can realize jet drilling in the formation at low speed( 0. 5 ～ 3. 0 mm/s),high thrust( 2 k N) and long distance( ≥ 10 m) drilling. The system ’ s drilling speed is consistent with the jet breaking rock velocity( 0. 3～5. 0 mm/s),which can maintain a relatively stable jet distance between the nozzle and the rock,and this is conducive to long-distance drilling. Under shallow burial depth,soft rock,large porosity,and low confining pressure and high temperature conditions,rock-breaking drilling efficiency is high,and vice versa. The research results can provide a certain reference for the further research and application of jet drilling technology.更多还原