inclination gauge and methods for examining earth formations

摘要

A disclosed embodiment (Fig. 2) utilizes one or more toroidal coil antennas (205, 215) mounted, in an insulating medium (206), on a drill collar (202) to induce currents which travel in a path that includes the drill collar (202) and earth formations around the drill collar (202). At least one array of electrodes (A1-A20) is provided on at least one stabilizer blade (220A) of the drill collar (202) and is utilized to detect currents transmitted by toroidal coil antennas (205, 215) which return via the formations to the electrodes (A1-A20) laterally; that is, approximately normal to the axis of the drill collar (202). Signal traces are obtained from measurements taken at respective ones of the transducers, and a dip characteristic of the formations is determined from the signal traces and from signals representing the rotational orientation of the drill collar (202). IMAGE