Research on Mud Pulse Signal Starting Time Extracting Algorithm in MWD

Abstract

The mud pulse signal extracting in MWD(Measurement while drilling) was a core technology in the oil drilling developing process. Determining how to accurately define the mud pulse signal starting time was a key issue affecting the decoding accuracy. This paper analyzed the transmission format of down-hole datum and transmission characteristics of mud pulse signal, using a wavelet multi-scale and related de-noising algorithm to extract mud pulse signal. On this basis, according to the characteristics of the underground encoded synchronization signal, It proposed an algorithm based on equal segmentations within a signal period to define the mud pulse signal starting time .The field tests show that the algorithm can accurately define the mud pulse signal starting time and can effectively improve the decoding accuracy and meet the requirements of engineering applications.