Research on New Drilling Downlink Communication Based on Anisotropic Magnetoresistive Technology

Abstract

With the continuous improvement of automatization of underground oil and gas resources exploitation, more and more instructions are required for the control technology while drilling in complex processes. The conventional downlink communication technology has shortcomings, such as data transmission lag and high bit error rate, which cannot meet the actual needs. Therefore, developing a new high-speed and low bit error rate (BER) downlink communication technology is very important. In this study, a new type of downlink communication system based on the electric current field is designed. Firstly, based on the theory of electromagnetic field and electromagnetic wave, the current distribution model of the drill string is established. Then, the magnetic field distribution model of the drill string is deduced according to the research on the static electromagnetic field and boundary problems. Finally, the ground simulation experiment platform of the downlink communication system is built and tested. The experimental results show that the BER is only 1.02% when the data transmission rate is 1 kbps. To further reduce the BER of the system, the influence factors of information transmission such as different transmitting voltage, inter-electrode distances, and working temperature are tested and analyzed, respectively, which provides ideas for optimizing the technology of downlink information communication while drilling.

Keywords

• anisotropic magnetoresistance detection
• current measurement
• downlink communication
• information transmission
• modulation and demodulation