The Current Status and Problems of Wireless Signal Transmission in Measurement While Drilling

In order to obtain measurement information in time while drilling and accurately set up"closed loop"communication between ground and the bottom of a well,the wireless signal transmission manner in measurement while drilling(MWD) was studied.It introduced working principle of three kinds of wireless signal transmission in MWD,such as drilling fluid pulse,electromagnetic wave and acoustic wave,compared advantages and disadvantages,and detailedly analyzed existed problems in three transmission manners.Finally,it pointed out the research emphases on the wireless signal transmission in MWD:drilling fluid pulse transmission method should develop continuous wave signal generator to realize high transmission efficiency,working reliability and environmental adaptability.Electromagnetic wave transmission method should optimize working frequency and efficiency of signal generator,study measurement and disposal weak signal,increase signal repeaters,and improve electromagnetic wave transmission distance.Acoustic wave transmission method should study from several aspects,such as intersymbol interference,noise and acoustic wave energy attenuation.