Abstract: A method for drilling a well includes applying a current across a drill collar that surrounds an internal magnetometer. The current travels across the drill collar and along one or more other current paths to return to the drill collar. The method also includes using the magnetometer to measure magnetic fields due to the current being applied across the drill collar and the current across one or more other current paths while the drill collar is disposed at a first angle of rotation and rotating the drill collar to a second angle of rotation. The method further includes measuring the magnetic fields using the internal magnetometer while the drill collar is disposed at the second angle of rotation and determining a relationship between the current across the drill collar and a portion of the magnetic fields due to the current across the drill collar measurable by the internal magnetometer.

Abstract: Systems and methods for improved acquisition of magnetic field data for magnetic ranging while drilling are provided. In one embodiment, such a system may include a borehole assembly and data processing circuitry. The borehole assembly may include an electric current driving tool configured to cause a current to flow across a drill collar of the borehole assembly and an internal magnetometer disposed within the drill collar and between the insulated gap and an end of the borehole assembly, which may be configured to measure magnetic field signals that penetrate the drill collar.