Patent ID: 9372276
Filing Date: 2016-06-21
CPC Classification: G01V

Claim Text:
1. An electromagnetic well logging instrument, comprising: an instrument housing; an antenna disposed on the housing, wherein the antenna comprises at least one saddle coil having first and second terminals and an axial coil having first and second terminals, wherein the saddle coil and axial coil are collocated and have respective dipole moments that are orthogonal with respect to one another, and wherein the first terminal of the axial coil and the first terminal of the at least one saddle coil have a first polarity and the second terminal of the axial coil the second terminal of the at least one saddle coil have a second polarity, the first and second polarities being opposite from each other; and an arrangement of switching devices that electronically connects the axial coil to the saddle coil, wherein the arrangement of switching devices is configured such that a first set of switches of the switching devices is operable to electronically couple the second terminal of the axial coil to the first terminal of the at least one saddle coil and a second set of switches of the switching devices is operable to electronically couple the second terminal of the axial coil to the second terminal of the at least one saddle coil; wherein the overall dipole moment of the antenna is an oblique dipole moment in a first direction when the second terminal of the axial coil and the first terminal of the at least one saddle coil are electronically coupled by the first set of switches and is the oblique dipole moment in a second direction when the second terminal of the axial coil and the second terminal of the at least one saddle coil are electronically coupled by the second set of switches, the first and second directions being opposite from each other.