Patent ID: 9291739
Filing Date: 2016-03-22
CPC Classification: E21B,G01V

Claim Text:
1. A system comprising: a three-axis magnetometer configured to determine a set of measurements over a period of time of a time-dependent magnetic field caused by one magnetic source at a single position rotating about an axis, wherein the set of measurements includes one axial component aligned with the axis and two transverse components transverse to the axis, wherein the two transverse components are perpendicular to one another and the measurements are made from a single location of the magnetometer at an observation point; and data processing circuitry configured to determine a transverse angle of rotation of the set of measurements, such that one of the two transverse components is in phase with the one axial component when the transverse angle of rotation is used to transform the set of measurements, and to determine a spatial relationship between the magnetic source and the three-axis magnetometer based at least in part on the transverse angle of rotation, wherein two or more bore holes or two or more wells are drilled having the spatial relationship with respect to one another.