Design of acoustic wireless remote transmission system for logging-while-drilling data

LWD data transmission is one of the key technologies for achieving intelligent drilling. Acoustic wave wireless transmission technology is a kind of LWD data transmission technologies. It takes the elastic waves propagating along the drill string as carrier to transmit measurement data to the ground. And it is an emerging, promising technology for LWD data distance transmission. However, acoustic noise being generated during drilling by the drilling equipment and mud circulation, and signal attenuation in the transmission medium and especially the high reflectivity of the pipe joints caused the impulse response of the drill string lasts for hundreds of milliseconds. All those can cause serious InterSymbol interference and eventually lead to the transmission capacity of the channel dropped significantly. To address this problem, after deeply analyzing the sound propagation characteristics of the drill string, project team proposes a transmission technology base d on SC-FDE technology. In order to improve the reliability and reduce the error rate of data transmission, the channel coding/decoding technology and signal modulation/demodulation techniques, which are suitable for acoustic transmission channel characteristics, are studied.