COIL WINDING METHODS FOR DOWNHOLE LOGGING TOOLS

摘要

A logging tool and method for winding a multi-component induction (MCI) antenna is presented. The method eliminates unwanted dipole signals that are created by the voltage drop that takes place in the transmitter. The antenna is made of at least two parts physically separated, one on each side of the mandrel. The winding method is performed in a way that creates at least four windings arranged to eliminate dipole signals attributable to an asymmetric voltage distribution. The midpoint of the conductive wire that for is the antenna windings may be electrically attached to the tool body. This method is suitable for the winding of the cross-components X and Y of the MCI coil arrays.

主权项

1. A logging tool having an antenna for transmitting or receiving signals with a magnetic field component orthogonal to a longitudinal tool axis, the antenna including at least two portions arranged on opposite sides of the longitudinal tool axis, the antenna comprising:
a conductive wire that forms at least two windings on each of the at least two portions, the conductive wire sustaining a voltage distribution along its length during operation of the antenna, the voltage distribution being symmetric about a midpoint of the conductive wire, and the windings being arranged so that each winding on each portion of the antenna is matched by another winding on that portion having an equal and opposite voltage distribution.