Method for eliminating pump stroke noise in mud impulse signals by aid of adaptive filtering algorithms

Abstract

The invention discloses a method for eliminating pump stroke noise in mud impulse signals by the aid of adaptive filtering algorithms. The method mainly includes three filtering steps implemented by the aid of an adaptive wave trap, an adaptive noise canceller and a FIR (finite impulse response) low-pass filter and particularly includes 1), filtering useful signals in original signals by the aid of the adaptive wave trap; 2), inputting the original singles into main channels of the adaptive noise canceller; 3), filtering the high-frequency noise in output signals of the adaptive noise canceller by the aid of the FIR low-pass filter so as to complete filtering. Reference signals at the step 2) are delay signals of the original signals without the useful signals, and error signals outputted by the adaptive noise canceller are the original signals without the pump stroke noise according to LMS (least mean square) criteria. The method has the advantages that the method can be used for carrying out noise removal processing on the mud impulse signals in measurement-while-drilling systems, effective filtering can be implemented on the premise that the useful signals are protected from being cancelled, the method is easy to implement, is universal in the aspect of mud impulse signal processing and has high practical value in the aspect of increasing signal-to-noise ratios of the mud impulse signals and reducing the communication bit error rates, and reliable filtering effects can be realized.

Description

technical field

[0001] The invention relates to the technical field of eliminating pumping noise in logging while drilling, in particular to a method for eliminating pumping noise in mud pulse signals by using an adaptive filtering algorithm. Background technique

[0002] In the wireless measurement-while-drilling system using mud as the medium, downhole information is transmitted to the ground in the form of mud pressure signals, and the ground system analyzes and processes these signals, and finally obtains the directional data, formation information and drilling parameters required for construction and other information. Due to the influence of factors such as high temperature, high pressure, strong vibration, and long-distance transmission on site, the signal detected by the wellhead mud pressure sensor includes not only the original pulse sequence signal, but also a large number of high-intensity noise signals caused by various mechanical vibrations. As the drilling de...

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