Patent ID: 6427784
Filing Date: 2002-08-06
Classification: E21B,G01V

Abstract:
A system for mapping a horizontal bore below a ground surface, said system comprising:an underground boring drill string having a boring head and a plurality of boring rods disposed behind said boring head; a first coil antenna disposed within said drill string proximate said boring head; transmitter circuitry disposed within said drill string in operative communication with said first antenna, said transmitter circuitry driving said first antenna so that said first antenna emits a magnetic field from said horizontal bore; a portable above-ground first receiver having first receiver circuitry and a pair of second coil antennas in operative communication with said first receiver circuitry, wherein said first receiver circuitry receives measurement signals from said second antennas corresponding to signals induced on said second antennas by said magnetic field and determines a depth of said first coil based upon said measurement signals, and wherein said portable first receiver includes a transmitter in communication with said first receiver circuitry and wherein said first receiver circuitry transmits wireless signals from said transmitter corresponding to said depth; and a second receiver remote from said first receiver, said second receiver having an operator-actuatable control, second receiver circuitry and a third antenna in operative communication with said second receiver circuitry so that when said third antenna receives said wireless signals, said second receiver circuitry receives signals from said third antenna corresponding to said depth, wherein said second receiver circuitry includes memory and a processor in operative communication with said memory and said control, wherein said processor stores, in said memory responsively to an operator instruction received through said control, data corresponding to said depth of said boring tool at a particular position of said boring tool in said horizontal bore, wherein said processor stores said data in association with an identifier that identifies the sequence of said depth data among a plurality of said depth data stored in said memory corresponding to respective said particular positions, and wherein said processor associates said depth data for said respective particular positions with actual ground level data that defines actual ground levels at said particular posotions relative to each other.