A continuous wave mud pulse signal extraction algorithm based on dual sensors

Mud pulse signal detection technology is an indispensable key technology in oil and gas drilling engineering, primarily used for downhole information transmission in Measurement. The transmission of mud pulse signals is affected by various noise interferences, among which the most significant interference originates from surface mud pump noise. Maximizing the elimination of pump noise and improving signal transmission efficiency is a critical challenge that urgently needs to be addressed in MPT systems. This paper proposes a novel continuous wave mud pulse signal extraction method based on dual sensors, which facilitates the reception and reconstruction of downhole mud pulse signals. The method leverages the opposite propagation directions of pump noise and downhole pulse signals, converting the time-shifted signals received simultaneously into phase-shifted signals and separating useful signals from pump noise through linear spatial transformation. Results demonstrate that this method effectively reduces complex pump noise in surface signals and successfully extracts downhole mud pulse signals. Under single-frequency noise conditions, the Signal-to-Interference-and-Noise Ratio (SINR) is improved from 1.3 dB to 16.9 dB, and under multi-frequency noise conditions, SINR is improved from 0.1 dB to 11.9 dB. This study not only provides new insights into signal detection technology in complex environments but also paves the way for further development of MWD systems and intelligent drilling systems.