Patent ID: 6057687
Filing Date: 2000-05-02
Classification: E21B,G01C,G01V

Abstract:
In a system in which a boring tool containing means for producing a dipole magnetic field is steered through the ground by means of a boring machine and in which the position of the boring tool during its movement through the ground is established by means of an above-ground receiver in cooperation with and responsive to said magnetic field, the improvement comprising:(a) said receiver which is configured to operate alternatively in first and second modes such that(i) the receiver, operating in said first mode positioned above ground, includes means responsive to said magnetic field for determining the particular location of the boring tool as the boring tool moves along said path from a first point to a second point, and(ii) the receiver, operating in said second mode positioned at a fixed point, includes means responsive to said magnetic field for establishing between said boring tool and said receiver a homing path along which said boring tool is steered toward said fixed point.