System and method employing a rotational valve to control steering in a rotary steerable system

摘要

A system and methodology provide improved control over the directional drilling of a wellbore. A rotational valve is mounted within a drill collar of a rotary steerable system to control flow of actuating fluid to one or more steering pads which are selectively moved in a lateral direction with respect to the rotary steerable system. The rotational valve is designed to provide enhanced control over the flow of actuating fluid to the steering pads to facilitate drilling of straight sections of wellbore and deviated or non-linear sections wellbore.