RELUCTANCE SENSOR FOR MEASURING A MAGNETIZABLE STRUCTURE IN A SUBTERRANEAN ENVIRONMENT

摘要

A drilling apparatus, sensor, system and method. The drilling apparatus includes a drill bit and a steering controller that steers the drill bit. The drilling apparatus includes a reluctance sensor system that measures changes in magnetic flux. The reluctance sensor includes two or more magnets creating a bucking effect. The drilling apparatus includes a processor in communication with the reluctance sensor that receives the measurements made by the reluctance sensor to determine a distance or direction to a target object. The distance is utilized by the steering controller to steer the drill bit.