Reaction torque minimization method for keeping drilling direction of the hybrid rotary steerable system

The directional drilling system is one of the key technologies for developing unconventional resources such as shale gas and coal bed methane (CBM). There are several types of the directional drilling system such as the whipstock, bent-sub, and the rotary steerable system (RSS). Among these systems, the RSS is most advanced system. In this paper, the hybrid type RSS is developed and its experiment results of drilling cement blocks will be introduced. The experiment had a problem due to the reaction torque of the drilling system. A method of minimizing the effect of the reaction torque is proposed to solve this problem.