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

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.