Patent attributes
A system for monitoring deflection of a downhole tool assembly. The system comprises a beam source directing a beam at a receptor positioned proximate the downhole tool assembly. The receptor detects the position of incidence of the beam at the receptor. A processor receives signals from the receptor and determines angular deflection of the downhole tool assembly based on incidence of the beam at the receptor. Information from other orientation sensors is also used to determine magnitude and direction of deflection. Deflection information is used by an operator or a control system to maintain or correct the course of the downhole tool assembly.