Patent ID: 11965408
Assignee: VECTOR MAGNETICS, LLC
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 13:
14. The method of claim 12, wherein prior to the processor of the at bit inclination and azimuth tool of the drilling assembly receiving magnetic and gravity field vector measurements from the first set of three axis inclinometer sensors and the first set of three axis magnetometer sensors of the at bit inclination and azimuth, the method further comprising calibrating the at bit inclination and azimuth tool by:
placing the at bit inclination and azimuth tool connected to the rotatable drill bit on roller supports connected to a rotatable platform at a borehole site;
leveling the rotatable platform such that a z-axis of the at bit inclination and azimuth tool and rotatable drill bit is level and points along magnetic north;
rotating the at bit inclination and azimuth tool and rotatable drill bit about a vertical axis of the at bit inclination and azimuth tool;
recording azimuth and z magnetometer sensor measurements from the at bit inclination and azimuth tool;
returning the z-axis of the at bit inclination and azimuth tool to an orientation of magnetic north;
with the z-axis fixed, rolling the at bit inclination and azimuth tool about the z-axis and record x and y magnetometer sensor measurements and a roll angle; and
calculating multipliers for calibration x magnetic field component, calibration y magnetic field component and calibration z magnetic field component and calibration remanent magnetic field components associated with the at bit inclination and azimuth tool and drill bit and storing in a repository.