Abstract: To overcome a number of bottlenecks in high-curvature horizontal wells, such as instability of large antitorque, inconformity of build-up rate, bit partially loadanddifficultcutting cleaning,PDC bits for special wellsaredesigned toexpand application spaceof PDC bits, improvethe applicationefficiency of bits for igneous and metamorphic rocks and meet the market demand of directional wells, horizontal wells and special rock drilling operation. A series of 14 new PDC bit products, such as φ152.4mm, φ215.9mm, φ241.3mm and φ311.15mm, have been successfully developed by means of spiral gauge, equal wearing teetharrangement, pre-breaking stress and cutterpress indepthcontrol.Thefieldapplicationofthosebitsin JidongOilfield,SuligeGas Field indicatethatthey can improve drilling speed, shorten drilling cycle and create good conditions for subsequent accurate logging and identification of oil and gas formations. This series of new products reached the domestic advanced level and have a promising prospect for application and extension. However, it is still necessary to make an in-depth study of the bits in the future in theareas of the cutting teethangleandrock-breaking efficiency.

Key words: PDC bits; special wells; cutter press in depth control; design characteristics; functional parameters

摘要： 为了解决水平井定向时反扭矩过大而造成的失稳、造斜率不一致、钻头偏载、岩屑清理困难等问题,研制的特殊井PDC钻头拓展了PDC钻头的应用空间,提高了火成岩和变质岩地层钻头使用效率,满足了定向井、水平井及特殊岩性钻井施工的市场需求。通过采用螺旋规径、等磨损布齿、预破应力和切削齿吃入控制等设计方法,成功开发了φ152.4mm、φ215.9mm、φ241.3mm、φ311.15mm等14种新型号PDC钻头产品。通过在冀东油田、苏里格气田等现场应用表明,运用这种钻头可提高钻井速度,缩短钻井周期,并为后续准确测井、识别油气层创造了良好的条件。该系列钻头新产品达到国内先进水平,具备良好的推广应用前景,对于钻头切削齿角度与破岩效率的研究今后仍需深入进行。

关键词: PDC钻头, 特殊井, 吃入控制, 设计特点, 性能参数