Digital signal receiver for measurement while drilling system having noise cancellation
First Claim
1. A method for reducing noise in a measured telemetry signal, comprising:
- tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal, the at least one harmonic having a frequency outside a telemetry signal band;
determining the characteristic of the noise component for at least one other harmonic thereof, the at least one other harmonic having a frequency inside the telemetry signal band, and generating a noise reference therefrom; and
combining the noise reference with the measured telemetry signal to generate a noise-canceled telemetry signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A method is disclosed for reducing noise in a measured telemetry signal. The method includes tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal band. The at least one harmonic has a frequency outside a telemetry signal band. The characteristic of the noise component is determined for at least one other harmonic thereof. The at least one other harmonic has a frequency inside the telemetry signal band. A noise reference is generated from the characteristic of the in band harmonic, and the noise reference is combined with the measured telemetry signal to generate a noise-canceled telemetry signal.
-
Citations
44 Claims
-
1. A method for reducing noise in a measured telemetry signal, comprising:
-
tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal, the at least one harmonic having a frequency outside a telemetry signal band;
determining the characteristic of the noise component for at least one other harmonic thereof, the at least one other harmonic having a frequency inside the telemetry signal band, and generating a noise reference therefrom; and
combining the noise reference with the measured telemetry signal to generate a noise-canceled telemetry signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A method for reducing noise in a measured telemetry signal, comprising.
tracking a frequency of at least one harmonic of a noise component in the measured telemetry signal, the at least one harmonic having a frequency outside a telemetry signal band; -
determining the frequency of the noise component for at least one other harmonic thereof, the at least one other harmonic having a frequency inside the telemetry signal band;
setting a notch filter to exclude the at least one other frequency; and
filtering the measured telemetry signal using the notch filter. - View Dependent Claims (21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
-
-
24. A method for measurement while drilling comprising:
-
measuring at least one parameter in a wellbore during the drilling thereof;
converting the measured parameter into a telemetry format in the wellbore and transmitting the telemetry format;
measuring a telemetry signal corresponding to the transmitted telemetry format;
tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal, the at least one harmonic having a frequency outside a telemetry signal band;
determining the characteristic of the noise component for at least one other harmonic thereof, the at least one other harmonic having a frequency inside the telemetry signal band, and generating a noise reference therefrom; and
combining the noise reference with the measured telemetry signal to generate a noise-canceled telemetry signal.
-
Specification