A Study On Mud Pulse While Drilling Tool Signal Transmission And Processing Methods

With the attenuation of oil resources,oil drilling work is also becoming increasingly difficult,the oil wells structure is increasingly complex,the crude oil exploitation depth is increasingly deep,data provided by exploitation equipment is increasingly large,acquisition of logging data is increasingly difficult.How to solve these problems is becoming a hot topic of relevant researchers.In drilling construction,adopts logging while drilling technology to obtain borehole trajectory and region geological parameters and other information,and transmits the underground information to ground analysis instrument to process the data.It is not only beneficial to the exploitation of the work,but also conducive to the further development of logging while drilling technology.With the development and progress of various technology,the well down hole data transmission mode transforms from the traditional cable transmission mode to wireless transmission mode,transmission speed develops from low speed transmission to high speed transmission.Currently,well down hole data wireless transmission mode is mainly divided into two modes of data transmission,mud pulse and electromagnetic pulse.Pulse signals in mud pulse data transmission can be divided into positive pulse signal,negative pulse signal and continuous wave pulse signal.The well down hole data wireless transmission signal mostly takes mud as the transmission medium.Mud pulse signal data transmission will take underground information to the ground in the form of mud pulse,then per-process the mud pulse signal to signal which can be recognized by processor using ground sensors and show the signal through the display in order to facilitate staffs for further operation.In this paper,we research the mud pulse while drilling tool signal transmission and processing methods,design the MC68HC711 microcontroller as the core processor to meet the practical requirements of the slurry pulse control circuit,use Manchester decoding method to realize the analysis and extraction of the mud pressure pulse signal,and select FIR digital filter to filter the pulse signal.The purpose is to effectively improve the ground instrument signal detection accuracy and reliability.