Development of Downlink Communication System for Steerable Drilling Application

In order to improve the reliability of information transmission in steering drilling system, the downlink instruction encoding and decoding based on the transmission mode of mud pressure pulses were researched. According to analyze the characteristics of mud pressure pulses, the scheme applied negative pulses to transmit downlink instructions was established. Furthermore, the receiving system which identified instructions by detecting the time difference between falling edges of adjacent pulses was developed. A series of field experiments have been conducted by using the system. Experimental results show that the download instructions applied the mud pressure negative pulses can be decoded reliably and the recognition ability of instructions is improved considerably.