Noise detection and suppression system for wellbore telemetry

摘要

Methods and apparatus are described for identifying and removing noise from borehole telemetry or control signals. A spectrum of the signal and of an approximated noise-free spectrum of the signals are generated and compared so as to identify frequencies at which noise occurs. The approximated spectrum is preferably generated by an averaging or integrating process which essentially results in a smoothened variant of the signal spectrum. The comparison includes dividing the signal spectrum by the approximated spectrum, and setting a threshold in the resulting dimensionless peak spectrum. The remaining parts of the peak spectrum are identified as noise. The dimensionless spectrum is found to have major advantages when having to identify noise frequencies.