Performance analysis of downhole acoustic communication in multiphase flow

Abstract

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. Keywords-downhole communication; multiphase flow; acoustic communication I.ambient multiphase noise by employing commonly used signal processing techniques such as wavelet denoising, Reed-Solomon encoding, adaptive equalization, Barker code synchronization and bandpass filtering, to name a few. A very high data rate is hard to achieve reliably in a multiphase flow; however, high date rate is not critical in downhole communication applications. The results from this study suggest that very low transmission frequency and high transmission power should be used to increase the communication distance. Morever, advanced modulation and coding techniques can significantly help to improve the low spectral efficiency and bandwidth of the acoustic multiphase channels.As an extension of current work, effect of different vertical and horizontal flow regimes and flow rates on acoustic communication needs to be investigated. It would be extremely useful to have experimental data for acoustic communication through oil/water and oil/water/gas flows. Acoustic communication for reliable data transmission is an invaluable technology for downhole communication and numerous other industrial applications where radio frequency communication is not feasible.

The effects of scaling and bends in a fiber‐optic modalmetric acoustic detector

“…When the acoustic amplitude to be detected increases, the output should not be distorted or attenuated. A highly sensitive device is useful for detecting very weak signals that may be suitable as a receiver for typical acoustic communications through metallic media, [1][2][3][4][5][6][7][8] where the ultrasound attenuation is very strong. Nevertheless, input signals of large amplitudes will produce distorted outputs that can be deleterious, even for digital communications using on-off key format.…”

“…Most telecommunication channels use electromagnetic carriers in the radio or optical domains. However, some physical media or applications, such as oil pipelines, 1 machine embedded sensing, 2 structural health monitoring, 3 transmission through metallic walls, 4 transmission through solid channels with various shape, material and size to explore the ultrasonic communication feasibility in diverse environments, 5 and metallic cables or pipes, 6,7 do not support the propagation of electromagnetic carriers. As a result, one may exploit acoustic carriers for data communications along short‐links, for example, telemetry of measurements data.…”

Toward the Internet of Underground Things: A Systematic Survey

“…The authors proposed a single carrier with frequency domain equalization (SC-FDE) to improve the reliability of the acoustic transmission along the pipe strings. The impact of multiphase flow was examined in [72] for downhole acoustic communication with amplitude shift keying and frequency shift keying modulation schemes. Moreover, the authors in [73] introduced the use of trellis coded modulation for downhole acoustic communication where a more realistic model of 1000 m depth was considered with an achievable data rate of up to 400 bps.…”

Wireless Monitoring of Downhole Pressure Based on Tubing Transmission

“…The first wireless transmission method has low transmission efficiency and is seriously affected by the properties of the fluid in the wellbore and the performance of the pump [15,16]. Due to the complex structure of the wellbore medium, the mutual interference of acoustic waves is serious and their signal processing method is complicated for the wireless transmission method of acoustic waves [17][18][19]. The third method usually uses tubing as a signal transmission medium [20][21][22][23].…”