Schlumberger Technology Corporation

James Ferris Whidborne

Martin Thomas Bayliss

Neilkunal Panchal

Wayne J Phillips

Hamid Alturbeh

A rotary controlled system includes first and second alternators electrically connected to one another via a DC voltage bus. The alternators may optionally be further mechanically connected to one another via corresponding rotationally coupled components (such as rotationally coupled stators). A first field oriented controller is electrically connected with the first alternator and configured to cause the first alternator to provide a constant DC voltage to the voltage bus. A second field oriented controller is electrically connected with the second alternator and configured to receive electrical power from the voltage bus and cause the second alternator to provide servo angular position control of the rotationally coupled components. The system may be employed in a downhole rotary steerable tool to provide servo angular position control of a roll stabilized housing.

Rotary steerable roll stabilized control system

A closed loop method for using model predictive control (MPC) to control direction drilling attitude includes receiving a demand attitude and a measured attitude. The received attitudes are processed using a closed loop MPC scheme to obtain an attitude error that may be further processed to obtain a corrective setting for a directional drilling tool. The corrective setting is then applied to alter the direction of drilling. The process of measuring the attitude, processing via the model predictive control scheme, and applying a corrective setting may be repeated continuously while drilling. The disclosed methodology is intended to provide for superior directional control during closed loop directional drilling operations.

Closed loop model predictive control of directional drilling attitude

A drilling tool in accordance to one or more aspects includes a processor and a steering device. The processor determines a demand attitude and an instantaneous drilling tool attitude, evaluates a control law to derive a control law tool face, and converts the control law tool face to an equivalent tool face. The steering device applies the equivalent tool face to control a drill attitude of the drilling tool.

Directional drilling attitude hold controller

A method and apparatus for controlling drilling, the method comprising ascertaining a current position and attitude of a drilling structure, obtaining a desired end point for the drilling structure, creating an optimized geometric Hermite curve path for the drilling structure from the current position and attitude of the drilling structure to the desired end point for the drilling structure and controlling a drilling of the drilling structure from the current position and attitude of the drilling structure to the desired end point for the drilling structure along the optimized geometric Hermite curve path.

Minimum strain energy waypoint-following controller for directional drilling using optimized geometric hermite curves

An attitude hold controller method includes receiving at a navigable apparatus a demand inclination and a demand azimuth with respect to a global coordinate system and determining at the navigable apparatus a demand attitude vector according to the received demand inclination and the demand azimuth. Determining at the navigable apparatus a current navigable apparatus attitude vector. Evaluating a control law using the current navigable apparatus vector and the navigable apparatus demand attitude to derive a control law tool face, converting the control law tool face to an equivalent tool face, and applying the equivalent tool face with the navigable apparatus to control the navigable apparatus attitude.

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Milton Keynes, United Kingdom

James Ferris Whidborne