Modelling Wave Transmission for Transient Flow and Amplitude-Frequency Characteristics of Tubular String in a Water Injection Well

Fluid wave code communication is used in layered water injection intelligent monitoring systems, but a model of fluid transient flow signal transmission still unknown. Impedance and transfer coefficient power theory were to describe waves the process tubular string well was built based on matrix method. The relationship between pressure discharge analyzed when moved along string, influence terminal impedance dip angle studied. Simulations showed that with standing distribution signals transmitted string. Moreover, volatility under different impedances analyzed. frequency selected according amplitude ratio two ends parameters characteristics velocity obtained by simulation analysis. tended decrease as gas content increased. As tube diameter–thickness increased, decreased. Taking data from Daqing Oilfield an example, two-layer test platform study fluctuation at points experiment condition depth 1400 m. It verified experiments changes downhole wellhead had good consistency during waves. Comparing experimental results numerical results, errors 0.69% 3.85%, respectively, indicating verification model. This provides theoretical support for