Performance analysis of downhole acoustic communication in multiphase flow

There is a growing demand for wireless communication in oil & gas industry to improve well performance and overcome challenges in exploration, drilling, and production. One of the important challenges for the next generation of smart well completions is downhole wireless communication. This article investigates performance analysis of acoustic communication through a multiphase flow in a pipeline. A laboratory test setup was built to investigate acoustic propagation through multiphase flow. Effect of various flow and communication parameters (multiphase flow regimes, transmission frequency, and modulation techniques) on acoustic data communication were studied. The pipeline acts as an acoustic waveguide in which the frequency content and spectrum of the transmitted acoustic signal affects the bit rata and communication range. A multiphase acts as a frequency dependent fading channel, where a water-air interface acts as a reflector and scatters the incoming acoustic wave and introduces severe reverberations and energy loss. Also, it is observed that multiphase channel has a dispersive and non-linear nature, where received signal can have time spreading and frequency shift from original transmitted waveform. To reduce distortion phenomena and achieve better communication in multiphase flow over short range, a number of signal processing and communication techniques are proposed.