Advanced underground homing system, apparatus and method

摘要

A boring tool that is moved by a drill string to form an underground bore. A transmitter transmits a time varying dipole field as a homing field from the boring tool. A pitch sensor detects a pitch orientation of the boring tool. A homing receiver is positionable at a target location for detecting the homing field to produce a set of flux measurements. A processing arrangement uses the pitch orientation and flux measurements with a determined length of the drill string to determine a vertical homing command for use in controlling depth in directing the boring tool to the target location such that the vertical homing command is generated with a particular accuracy at a given range between the transmitter and the homing receiver and which would otherwise be generated with the particular accuracy for a standard range, different from the particular range. An associated system and method are described.

主权项

1. In a system including a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable and in which the boring tool is configured for transmitting a time varying electromagnetic homing field, an apparatus comprising:
an arrangement that is configured for using at least the time varying electromagnetic homing field in conjunction with a determined length of the drill string to generate a vertical homing command and a horizontal homing command such that the vertical homing command has a particular accuracy that is different from another accuracy associated with the horizontal homing command for use in controlling depth in directing the boring tool to a target location.