Research On Deep Well Acoustic Wave Communication Technology

As an important field of intelligent logging technology,sonic logging technology has great advantages in promoting intelligent logging technology compared with traditional logging technology,which has the advantages of wireless transmission,low cost,fast transmission rate and stable channel.Among them,the downhole channel transmission characteristics and the rapid and stable transmission of downhole signals to the surface platform are the key technologies for studying deep well acoustic wave communication.Starting from the theory of elastic wave propagation in solids,the principle of wave motion is analyzed.Apply it to the deep well channel and use the longitudinal wave as the signal carrier to model the deep well channel.Firstly,the transmission characteristics of deep well channels are discussed from the traditional method.Then,the transfer matrix method is used to analyze them,periodic and aperiodic channels are used respectively.Both of these channels exhibit a frequency response characteristic in which the pass-stop bands alternate.For more in-depth research,the effects of the length and cross-sectional area of periodic deep well pipes and different combinations of non-periodic deep well pipes on transmission performance are analyzed.Based on the theory of wireless communication,the deep well wireless communication technology is analyzed,and the deep well acoustic OFDM transmission system model is established according to the characteristics of deep well channel comb filtering.The in-depth analysis is carried out from the transmitting and receiving ends of the system.The transmitter analyzes constellation mapping,guard spacing,and pilot design.The receiver uses S&C algorithm and frequency offset estimation to study the impact on system performance.The LS algorithm and DFT-LS algorithm are used to compare the system performance.The characteristics of ZF equalization technology and MMSE equalization technology are analyzed.From the theoretical analysis and simulation,the feasibility of the transmission system and the stability of the performance are verified.Finally,based on the particularity of the application scenarios of the Sham Tseng communication system,the overall design scheme is proposed for reference.The ideas and design suggestions are introduced from different aspects,such as the transmission circuit,the receiving circuit,the underground transmission system,the relay system,the transmission system on the well,and the power supply selection.