An Effective Approach for the Noise Removal of Mud Pulse Telemetry System

Mud pulse telemetry is a method used for measurement-while-drilling (MWD) in the oil industry. Information (tool-face orientation, temperature, pressure etc.) which is modulated by means of pulse positioning modulation (PPM) is sent from the bottom of the well to the surface by means of pressure waves in the drilling fluid (the drilling mud). Due to the influence of kinds of noise, the noise removal before decoding is of great importance. Considering the drilling fluid pulse´s depending on the position and the width of the pulse to transmit the information, after the description of the mud pulse telemetry system and the analysis of the received signal, a new method based on the digital filter to process the signal received from the down-hole to recover the useful signal is applied. The result and the decoding process indicate that all of the pump noise, the reflection noise and other random noise can be wiped off, and the received signal can be recovered effectively and decoded with low error rate.