Patent ID: 6095260
Filing Date: 2000-08-01
Classification: E21B,H01Q

Abstract:
A method of tracking the position and certain orientation parameters of a boring tool in the ground as the boring tool moves along a path which lies within a particular coordinate system, said method comprising the steps of:(a) providing the boring tool with means for transmitting an electromagnetic field;(b) providing only one detector, the detector having an electromagnetic field receiving antenna assembly including at least one antenna,positioning the detector provided at a fixed position and at a particular orientation within said coordinate system, anddetermining the position and particular orientation within said coordinate system of the antenna associated with the detector provided;(c) at least periodically transmitting said electromagnetic field from said boring tool when the boring tool is at certain positions on said path;(d) when the boring tool is at one point on said path, establishing its position and said certain orientation parameters of the boring tool within the coordinate system;(e) moving said boring tool along said path which includes said one point and at least a subsequent second point;(f) when the boring tool moves a distance along said path from said one point to said second point, measuring at least one component of the intensity of said electromagnetic field using said detector; and(g) determining, at least to an approximation, the position and orientation of the boring tool at said second point within the coordinate system using as a first input the electromagnetic field intensity measurement or measurements taken by said detector when the boring tool is at said second point, the position of said boring tool at said one point and said certain orientation parameters of the boring tool at said one point being used along with said electromagnetic field intensity measurement or measurements to determine, at least to an approximation, the position of the boring tool and said orientation parameters at said second point.