Robotic Controlled Drilling: A New Rotary Steerable Drilling System for the Oil and Gas Industry

摘要

Abstract The paper reviews the development of a second-generation rotary steerable drilling tool. The principle of operation is a bendable shaft that points the bit in the opposite direction to the shaft bending direction. This tilting action is a departure from other rotary steerable device concepts that push the bit sideways to change the wellbore trajectory. Combining this tilting action with extended gage bit technology provides maximum effectiveness in torque and drag reduction while reducing vibration and further improving hole cleaning. Important to the tool development was basing the design on lessons learned by others thereby improving both performance and reliability. The paper also discusses the application of proven technology from outside the drilling industry. Core elements such as strain wave gearing transmissions and electrically operated clutches were developed initially for use in industrial robots. Other significant elements are examined such as the shaft design, rotary seal systems and anti-rotation devices to limit housing roll rate. The "steering system" was integrated with an existing MWD system to allow automated or manual control from surface using a bi-directional communication system. This is also discussed.