Differential signal extraction for continuous wave mud pulse telemetry

Continuous wave mud pulse telemetry system with a transmission rate of more than 12 bps, is an irreplaceable high-speed data transmission technology for Measurement While Drilling (MWD) and Logging While Drilling (LWD) instruments used in modern oil drilling services. However, the valid signal is difficult to be obtained because of the disturbing of pump noise in the data transmission. Here, a differential signal extraction method for continuous wave mud pulse generator is applied to extract the effective mud pulse signal from pump noise. It utilizes dual sensor and a differential algorithm to extract the signal. To verify this method, the robustness was analyzed in the numerical simulation. In the actual test, a continuous wave mud pulse generator was designed, and a hydraulic circulation laboratory was built. The Signal to Noise Ratio (SNR) was risen from −13 dB up to 25 dB. The experimental results demonstrated the effectiveness of the designed mud pulse generator, and proved that this method can be a feasible way to solve the problem of signal extraction from pump noise.