Patent ID: 9371725
Filing Date: 2016-06-21
CPC Classification: E21B,G01V

Claim Text:
1. In a system for tracking a boring tool which moves in an underground region having an overall orientation that is characterized by a pitch orientation, a roll orientation and a yaw orientation and said boring tool is steerable underground in the region using said roll orientation, said boring tool being configured for advancing in a straight ahead mode during a continuous roll and further being configured for advancing in a steering mode by moving the boring tool at a fixed roll orientation, a method comprising: establishing a series of spaced apart positions as the boring tool is advanced across a segment of an overall path taken by the boring tool in said region and which positions are separated by an at least generally equal increment; measuring a series of incremental roll positions, corresponding to said series of positions; and based on the incremental roll positions, selecting an operational status of the boring tool over said segment as one of the straight ahead mode, the steering mode and a mixed mode which includes the straight ahead mode and the steering mode.