Abstract: Like conventional steerable screw drill, steerable screw drill with adjustable bent shell and exchangeable stabilizer is also used in drilling operation for directional wells, horizontal wells and fishbone laterals. Different from conventional steerable screw drill, the bent angle of the bent shell of universal coupling can be freely adjusted without dismantling the drill tool. The bent angle is usually adjusted within a scope of 0-3°. The near-bit stabilizer can be freely replaced without dismantling the drill tool. The size of stabilizer is usually 3.175-12.7mm less than the size of hole. The structural and engineering parameters of steerable screw drill can be adjusted in real time on the drilling operational site according to the concrete working conditions, thus improving the flexibility of service tool and controllability of operational process. This help improve drilling engineering quality and lower drilling cost. This article also proposes to continue optimization design in order to solve the problems related to the existing adjustable bent shell and on-site change of replaceable stabilizer.

Key words: steerable screw drill; adjustable bent shell; replaceable stabilizer

摘要： 带可调弯壳体和可换稳定器的导向螺杆钻具与常规导向螺杆钻具一样都是用于定向井、水平井、分支井等的钻井作业,与常规导向钻具不同的是万向轴弯壳体的弯角度可在无需拆开钻具的情况下任意调节,弯角度调节范围一般为0～3°,近钻头稳定器可在无需拆开钻具的情况下任意更换,稳定器尺寸一般可比井眼尺寸小3.175～12.7mm。钻井施工现场可根据具体工况需要实时调整导向螺杆钻具的结构及工程参数,从而提高了作业工具的灵活性和施工过程的可控性,有利于提高钻井工程质量,降低综合钻井成本。并对现有可调弯壳体螺纹易松脱、过大尺寸螺纹式可换稳定器现场更换不便的问题,提出继续优化设计的建议。

关键词: 导向螺杆钻具, 可调弯壳体, 可换稳定器