METHODS AND SYSTEMS FOR DETERMINING ANGULAR ORIENTATION OF A DRILL STRING

摘要

Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill string, so that the control input can be used to initiate a response in the rotating component as a function of gravity tool face.