Use of electrodes and multi-frequency focusing to correct eccentricity and misalignment effects on transversal induction measurements
AssigneeBaker Hughes Incorporated
InventorsMichael B. Rabinovich, Alexandre N. Bespalov, Stanislav W. Forgang
Life of this patent
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Abstract
A multicomponent induction logging tool uses a nonconducting mandrel. A central conducting member including wires that electrically connect at least one of the antennas to another of the antennas. Electrodes disposed about the transmitter antenna form a conductive path through a borehole fluid to the central conducting member.
Claims15
An apparatus for determining a resistivity property of an earth formation, the apparatus comprising:
- a logging tool having a non-conductive mandrel;
- a transmitter antenna;
- a pair of receiver antennas wherein an output of the pair of receiver antennas responsive to an activation of the transmitter antenna corrects for a misalignment of the transmitter antenna and the pair of receiver antennas;
- a central conducting member that electrically connect at least one of the receiver antennas to another of the receiver antennas;
- and
- a pair of electrodes disposed about the transmitter antenna forming a conductive path through a borehole fluid to the central conducting member.
A method of determining a resistivity property of an earth formation, the method comprising:
- conveying a logging tool having a non-conductive mandrel, a transmitter antenna, a pair of receiver antennas and a central conducting member that connect at least one of the antennas to another of the antennas, into a borehole;
- positioning a pair of electrodes about the transmitter antenna and forming a conductive path through a borehole fluid to the central conducting member;
- activating the transmitter antenna at a plurality of frequencies;
- receiving signals in the pair of receiver antennas responsive to the activation of the transmitter antenna;
- performing a multi-frequency focusing (MFF) of the signals received from the receiver antennas;
- and
- determining the resistivity property of the earth formation using results of the MFF.
A non-transitory computer-readable medium product having thereon instructions that, when read by a processor, cause the processor to execute a method, the method comprising:
- conveying a logging tool having a non-conductive mandrel, a transmitter antenna, a pair of receiver antennas and a central conducting member that connect at least one of the antennas to another of the antennas, into a borehole;
- positioning a pair of electrodes about the transmitter antenna and forming a conductive path through a borehole fluid to the central conducting member;
- activating the transmitter antenna at a plurality of frequencies;
- receiving signals in the pair of receiver antennas responsive to the activation of the transmitter antenna;
- performing a multi-frequency focusing (MFF) of the signals received from the receiver antennas;
- and
- determining the resistivity property of the earth formation using results of the MFF.
Dependencies are inferred from the claim text.