Design and Implementation of Closed-Loop Control of Vector Force in Static Push-the-bit Rotary Steering System

Rotary steering systems (RSSs) have been increasingly used to develop horizontal wells. A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the pushing force acting on the wellbore in different sizes and directions within a circular range, ultimately allowing the wellbore trajectory to be drilled in a predetermined direction. By analyzing its mathematical principles and the actual characteristics of the instrument, a vector force closed-loop control method, including steering and holding modes, was designed. The adjustment criteria for the three hydraulic modules are determined to achieve rapid adjustment of the vector force. The theoretical feasibility of the developed method was verified by comparing its results with the on-site application data of an imported rotary guidance system.