Method and apparatus for internal calibration in induction logging instruments
AssigneeBaker Hughes Incorporated
InventorsOtto N. Fanini, Stanislav W. Forgang, Michael S. Crosskno
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Abstract
The present invention improves measurement of the formation induction response in the presence of the primary magnetic field generated by a logging tool's transmitter. A structure is provided having a new combination of electrical and mechanical design features which provide logging tool for internal calibration and checking of antenna performance and characteristics before during and after well logging operations.
Claims13
An apparatus for sensing antenna performance in an induction logging tool having a transmitter and a receiver in the induction logging tool, the apparatus comprising:
- a magnetic field generating mechanism including a bucking coil configured to be coupled to the transmitter, and to the receiver through a switch, and
- a processor configured to process a signal from the receiver and sense antenna performance in the induction logging tool.
A method of sensing antenna performance in an induction logging tool comprising:
- deploying an induction logging tool including a transmitter and a receiver in a bore hole;
- electromagnetically coupling a magnetic field generating mechanism to the transmitter;
- coupling a bucking coil in the field generating mechanism through a switch to the receiver;
- using the field generating mechanism to provide a first signal upon activation of the transmitter and a second signal in the receiver;
- and
- using the first signal and the second signal for sensing antenna performance.
Dependencies are inferred from the claim text.