Electromagnetic Induction Based Short-distance Wireless Data Transmission And Its Application In Measurement While Drilling

As the petroleum drilling technology become more and more intelligent and informational, measurement while drilling bearing more and more important role in drilling operation. Electromagnetic induction based short-distance wireless data transmission is an effective method of achieving measuring and controlling while drilling.But the violent vibration, high temperature and high pressure, slurry medium and electromagnetic interference problems has brought the huge challenge to Electromagnetic Induction based short-distance wireless data transmission. So choose what method of data transmission, analysis of the influence of underground complex environment on the electromagnetic induction mechanism, using what way to weaken this effect become the focus in the study of this article.According to the requirements of data transmission between downhole tools and ground platforms in effective in measurement while drilling, after studying the advantages and disadvantages of data transmission way existing in the measurement and control, the control system based on RFID technology and electromagnetic induction short-distance wireless data transmission technology is put forward. Research is mainly focused on the electromagnetic induction based short-distance wireless data transmission system.Circuit model and physical model of the coupler are established, Analysis of the influence of metal pipe and mud medium to the properties of magnetic induction channel communication. Ferrite beads coupling structure is proposed and use to weaken the influence of complex environment to magnetic induction channel communication performance. Design of the optimal solution of the structure parameters of ferrite ring.The modulation and demodulation of the FSK signal is selected by comparing three common modulation and demodulation. A modem circuit is designed on AD9834 and SE564. The control program of modem chip and algorithms is written. An amplifying circuit is designed on OPA2674. A data transmission direction selection circuit is designed onTS5A12301 E. The half-duplex communication with data transfer rate 120 KBPS is completed.The experimental system of electromagnetic induction transmission is established.The influence of the metal pipe, mud environment and coupler structure parameters to coupling performance of the system is tested. The test results and finite element analysis results are compared, founding that the test results and finite element analysis results are anastomotic. A rationality of the optimal solution of the structure parameters of ferrite ring is verified.The Integration testing and reliability test of the system based on RFID technology and electromagnetic induction short-distance wireless data transmission technology is completed. The system through the field test, and successfully exhibiting the 15 th China international petroleum and petrochemical technology and equipment exhibition(CIPPE).