APPARATUS AND METHOD FOR ALIGNING DOWNHOLE MEASUREMENTS

摘要

Apparatuses and methods are described, such as for aligning downhole measurements. Apparatuses and methods include an arrangement of at least two tilted transmitters and at least one tilted receiver along a longitudinal axis of the tool. A first and second plurality of azimuthal measurements are processed to provide a first and a second plurality of higher order mode signals configured to be time-shifted.

主权项

1. A method of aligning a plurality of downhole electromagnetic measurements, comprising:
activating, at an initial recording time, a first transmitter antenna in an arrangement along a longitudinal axis, the first transmitter antenna activated at an operating frequency; activating, at the initial recording time, a second transmitter antenna in the arrangement, the second transmitter antenna disposed longitudinally from the first transmitter antenna along the longitudinal axis, the second transmitter antenna activated at substantially the same operating frequency as the first transmitter antenna; collecting at a first receiver antenna a first plurality of azimuthal measurements associated with the first transmitter antenna; collecting at a second receiver antenna a second plurality of azimuthal measurements associated with the second transmitter antenna; processing the first plurality of azimuthal measurements to produce a corresponding first plurality of higher order mode signals; processing the second plurality of azimuthal measurements to produce a corresponding second plurality of higher order mode signals; accumulating the first plurality higher order mode signals while the first transmitter antenna and the first receiver antenna are moved downhole, to form a first accumulated signal; accumulating the second plurality higher order mode signals while the second transmitter antenna and the second receiver antenna are moved downhole to form a second accumulated signal; and aligning the first plurality of higher order mode signals and the second plurality of higher order mode signals in the time-domain by a time-shift based on the first accumulated signal and the second accumulated signal.