Optimization of pressure wave encoding communication technology in offshore wells based on Euler-Moment model

A novel pressure wave coding communication technology for water injection wells has enabled precise control of layered injection flow rates in offshore oilfields in China, but irregular pressure waveform deviations caused by uneven solid particle distribution and the solid-liquid two-phase water hammer effect limit its large-scale application. This study establishes an Euler-moment model to simulate fluctuating wellbore pressure during communication and proposes a dynamic threshold segmentation method to optimize pressure signal acquisition. An improved pressure wave coding communication system is developed and validated through numerical simulations and field tests. Simulations reveal directional deviations in pressure signals: values decrease during downward communication and increase during upward communication, with a maximum deviation of 0.058 MPa and an average of 0.034 MPa. Field tests show significant improvements: single pressure code element duration is reduced from 6 to 3 minutes, error rates drop by 79%, recognition delay rates decrease by 57%, and system stability improves by 29%. Water injection command adjustment time is shortened by over 47%. This research enhances the efficiency of wellbore pressure wave communication, providing theoretical and practical guidance for its multi-scenario application and commercialization in petroleum engineering.