In straight sections, the sensor can make an automatic adjustment in a fast-response, closed-loop system to keep a specific inclination and azimuth. A six-axis component uses an extended-range sensor to facilitate enhanced HIA for better automatic attitude control to drill more deviated wells. The PowerDrive Orbit RSS can perform multiple functions in one run and achieve higher revolutions per minute (RPM), especially in situations of dogleg severity (DLS). By establishing deep kickoff points, the tool reduces inclination in unstable formations and footage to the reservoir. The first features dogleg capability up to 17° to 20° per 100 ft, providing control in unconsolidated formations and pushes through hard stingers. The advanced HIA system has been implemented in two Schlumberger PowerDrive RSS tools, the PowerDrive Archer hybrid RSS and the PowerDrive Orbit RSS. The continuous measurements allow the trajectory-following algorithm of the RSS to drill lateral sections more precisely.

The new survey method, using near-bit sensors, improves the inclination and azimuth measurement in near-vertical angles, enhancing the automated vertical drilling feature and providing a more accurate kickoff. The automated steering mode is enabled by downhole trajectory-control algorithms that make frequent, small adjustments to the RSS steering parameters, comparing near-bit continuous survey data with the target attitude.

This reduces reliance on a previously computed survey model and the need to stop drilling to take individual confirmation (static) surveys with conventional measurement-while-drilling (MWD) tools. The continuous automatic hold inclination and azimuth (HIA) capability reduces human-machine interaction by using a continuous real-time measurement of inclination and azimuth to optimize control of the trajectory and minimize wellbore tortuosity. Field tests in US shale plays shown improved efficiency. The new downhole steering and measurement algorithms are taking RSS to the next level in steering capability and downhole survey methods. As the drilling industry moves toward greater automation, RSS has been further enhanced with the capability for automated steering in tangent sections, including the vertical and lateral sections. Over the years, continued advances have expanded the operating window of RSS. When they were introduced in the mid-1990s, rotary steerable systems (RSS) represented a step-change in directional drilling.

Continuous automatic hold inclination, azimuth capabilities enhance automated steering, enable continuous directional measurementīy Junichi Sugiura, Peter Hornblower, Richard Hawkins, Ross Lowdon, Aboyi Olokpo and Cesar Figueredo, Schlumberger Figure 1: The PowerDrive Archer hybrid RSS can deliver high build rates from any inclination.

Archer directional drilling