Feasibility Study of While-drilling Data Transmission Technology Basedon Radio Frequency Identification

Downhole data transmission methods based on mud-pulse and low-frequency electromagnetic waves can't sat- isfy the need of large amount and high speed data uploading during drilling. In this paper, a novel data transmission tech- nique based on releasing RFID tags by LWD tools is designed and validated. As the memory and transmission media, RFID tags are pre-mounted tactfully in cavities of the downhole releasing tool which can transmits/write LWD data to these tags. By releasing regularly or irregularly into the annulus fluids, RFID tags can be carried to the surface by mud circulation. To finish data transportation function, LWD data can be read out on the surface. Wireless charging high ca- pacity (1Mbits) RFID tags are designed, which contains microprocessor and memory, to expand the storage capacity of RFID tags. The power supply for microprocessor and memory in the tag is electromagnetic waves from RF Reader/Writer module. The equivalent data transmission speed of this system can be up to 278 bit/s (1 tag/h is assumed), which is more much faster than the traditional mud pulser (<10 bit/s).