关键词: 定向钻井套筒型钻井变向器, 三维分析, 三弯矩方程, 钴杆接头, 参数优选

Abstract: This paper put emphasis on the researches of Shell-type Azimuth Controller (STAC Tool) for rotary drilling. A new drilling technique of using STAC Tool assembly to control drilling trajectories is proposed and developed. It can be used without down hole mud motor with a bent sub, speed up ROP and improve the drilling quality. This is one of the innovations in drilling techniques. In this paper, a quantitative three-dimensional mechanical analysis has been made by using beam-column theories; three dimensional analysis method of STAC is developed and applied to complete theoretical computations. The results indicate that azimuth can be adjusted and improved by changing some parameters; harmful effects of hole enlargement can be overcome and inclination can be increased by attaching a bent sub at the bottom of the tool. This paper deducted the inherent regularities that influence the new technique. All of these shows that STAC Tool can be extensively used in deviation control. Through practical drilling practices in the Daqing Oilfield and the Liaoho Oilfield, satisfactory results have been achieved, which shows an agreement between theories and practise. Thus this technique can be field applied.