Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A feedback control system for steering a tool along a well-plan. Optimum steering instructions may be generated by a recursive optimization of multiple objectives. These objectives can include accuracy and quality. The quality objective can include the objective of drilling a smooth borehole by minimizing strain energy and torsion. The accuracy objective can include the objective of minimizing the deviation of the borehole trajectory during the real-time drilling process from a predefined well-plan. The trajectory control problem, therefore, can be a multi-objective problem where, in some embodiments, the weightings of the individual objectives can be adjusted along the process.

Abstract: Methods and systems for generating a well-plan with respect to geological targets. The well plan can be optimized for strain energy and torsion, to generate a smooth borehole. The resultant path can be constrained for curvature which is a design parameter and can produces a path feasible for a directional steering tool to achieve. The method can be constructed as a convex optimization problem, and/or provide a unique solution by interior point methods.

Abstract: 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.

Abstract: A launching device for a clay target including a throwing arm supported to be rotatable continuously about an axis, and including means to load a clay target substantially at said axis, wherein the throwing arm includes an escapement mechanism operable between a first position in which a clay target is prevented from being launched from the throwing arm and a second position in which a clay target is permitted to be launched from the throwing arm. Loading means may be provided including a resilient loading receptacle located substantially at the axis to provide cushioning to a clay target as it is loaded. Further, the throwing arm may include a base portion for bearing a clay target and a top cover spaced from the base portion and adapted to disrupt the airflow over the clay target.