地热定向井高效PDC钻头研制与应用

Development and application of high-efficiency PDC bit for geothermal directional wells

摘要:

为解决天津东丽区块地热定向井施工效率偏低的技术问题，针对该区块的地层特性开展了高效PDC钻头定制化研发。通过优化设计钻头剖面结构和布齿密度，结合仿真分析与室内试验，对比三棱齿和平面齿的破岩受力特征及应力分布规律，优选三棱齿作为主切削齿；采用UG-CAM五轴加工与等离子自动焊接复合加工工艺，保障钻头加工精度与耐磨性能。现场应用数据表明，新研发的PDC钻头在DL-93地热定向井中累计进尺460.58 m，平均机械钻速达3.68 m/h，较邻井常规PDC钻头提升41%，可满足该地区地热定向井高效钻进需求。

Abstract:

To address the technical problem of low construction efficiency of geothermal directional wells in the Dongli Block of Tianjin， customized research and development of high-efficiency PDC drill bits was carried out targeting the formation characteristics of this block. By optimizing the drill bit profile structure and tooth arrangement density， combined with simulation analysis and laboratory tests， the rock-breaking force characteristics and stress distribution laws of triangular prism cutter and plane cutter were compared， as a result， the triangular prism cutter were selected as the main cutters. A composite processing technology integrating UG-CAM five-axis machining and plasma automatic welding was adopted to ensure the machining accuracy and wear resistance of the drill bit. Field application data show that the newly developed PDC bit achieved a total footage of 460.58m in the DL-93 geothermal directional well， with an average rate of penetration （ROP） of 3.68m/h， which is 41% higher than that of the conventional PDC drill bits in adjacent wells， meeting the requirements for efficient drilling of geothermal directional wells in this area.