Patent ID: 11898432
Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 11:
12. A method for drilling a subterranean wellbore, the method comprising:
(a) rotating a drill string in the subterranean wellbore to drill, the drill string including a drill collar, a drill bit, a roll-stabilized housing deployed in the drill collar, and a triaxial accelerometer set, a triaxial magnetometer set, and at least one gyroscopic sensor deployed in the roll-stabilized housing;
(b) causing the triaxial accelerometer set, the triaxial magnetometer set, and the gyroscopic sensor to make corresponding triaxial accelerometer measurements, triaxial magnetometer measurements, and gyroscopic sensor measurements while the drill string is rotating in (a);
(c) combining the triaxial accelerometer measurements and the gyroscopic sensor measurements made in (b) to obtain accelerometer measurements;
(d) processing the triaxial magnetometer measurements to remove magnetic interference from the magnetometer measurements and to obtain corrected magnetometer measurements wherein the processing comprises:
i) filtering cross-axial components of the triaxial magnetometer measurements to remove cross-axial magnetic interference and obtain filtered cross-axial magnetic field measurements; and
(ii) processing the filtered cross-axial magnetic field measurements to remove magnetic interference induced by eddy currents flowing in the rotating drill collar to obtain corrected cross-axial magnetic field measurements; and
(e) processing the accelerometer measurements obtained in (c) and the corrected magnetometer measurements obtained in (d) to compute survey parameters of the subterranean wellbore while drilling in (a), the survey parameters including at least a wellbore azimuth.