Intrusive and non-intrusive microflow measurement based on distributed optical fiber acoustic sensing

•Distributed acoustic sensing (DAS) is used for flow monitoring, which overcomes complex networking and limited monitoring range in single-point flow measurement.•An exponential relationship between flow rate and pressure is obtained through theoretical analysis and validated by intrusive and non-intrusive simulations.•Through distributed experiments, the intrusive monitoring is verified to have a better degree of fitting up to 0.99432 and uncertainty less than 1%.