Tilted Test Loop Calibration System
AssigneeSchlumberger Technology Corporation
InventorDursun Sedat Kilic
Life of this patent
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Abstract
A tilted test loop for use in calibrating an electromagnetic logging tool includes a substantially cylindrical hub, a planar elliptical frame connected to the hub and oriented at a tilt angle with respect to a longitudinal axis of the hub, at least one triangular wedge connected to the hub and the planar frame, the triangular wedge having an angle that defines the tilt angle, and a plurality of elliptical conductive loops deployed in corresponding elliptical grooves in the frame.
Claims20
A tilted test loop for use in calibrating an electromagnetic logging tool, the tilted test loop comprising:
- a substantially cylindrical hub having a longitudinal axis and a through bore sized and shaped for deployment about the electromagnetic logging tool;
- a planar elliptical frame connected to the hub and oriented at a tilt angle with respect to the longitudinal axis of the hub;
- at least one triangular wedge connected to the hub and the planar frame, the triangular wedge having an angle that defines the tilt angle;
- and
- a plurality of elliptical conductive loops deployed in corresponding elliptical grooves in the frame.
A system for calibrating an electromagnetic logging tool, the system comprising:
- an electromagnetic logging tool having a tool body, a plurality of transmitter antennae, and a plurality of receiver antennae;
- a tilted test loop deployed on the electromagnetic logging tool, the tilted test loop including (i) a substantially cylindrical hub deployed about the electromagnetic logging tool, (ii) a planar elliptical frame connected to the hub and oriented at a tilt angle with respect to a longitudinal axis of the hub, (iii) at least one triangular wedge connected to the hub and the planar frame, the triangular wedge having an angle that defines the tilt angle, and (iv) a plurality of elliptical conductive loops deployed in corresponding elliptical grooves in the frame;
- and
- a processor including instructions to (a) cause one of the transmitter antennae to transmit an electromagnetic wave, (b) cause one of the receiver antennae to receive the transmitted electromagnetic wave, and (c) process the received electromagnetic wave to compute a calibration of the electromagnetic logging tool.
A method for calibrating an electromagnetic logging tool, the method comprising:
- (a) deploying a tilted test loop about the electromagnetic logging tool, the tilted test loop including (i) a substantially cylindrical hub deployed about the electromagnetic logging tool, (ii) a planar elliptical frame connected to the hub and oriented at a tilt angle with respect to a longitudinal axis of the hub, (iii) at least one triangular wedge connected to the hub and the planar frame, the triangular wedge having an angle that defines the tilt angle, and (iv) a plurality of elliptical conductive loops deployed in corresponding elliptical grooves in the frame;
- (b) configuring the tilted test loop such that a single one of the plurality of conductive loops is closed and all others of the plurality of conductive loops are open;
- (c) causing a transmitter antenna on the electromagnetic logging tool to transmit an electromagnetic wave;
- (d) causing a receiver antenna on the electromagnetic logging tool to receive the electromagnetic wave transmitted in (c);
- and
- (e) causing a processor to compute a calibration for the electromagnetic logging tool from the electromagnetic wave received in (d).
Dependencies are inferred from the claim text.