Investigation on dynamic calibration for an optical-fiber solids concentration probe in gas-solid two-phase flows

Non-Intrusive Pipeline Flow Detection Based on Distributed Fiber Turbulent Vibration Sensing

We demonstrate a non-intrusive dynamic monitoring method of oil well flow based on distributed optical fiber acoustic sensing (DAS) technology and the turbulent vibration. The quantitative measurement of the flow rate is theoretically acquired though the amplitude of the demodulated phase changes from DAS based on the flow impact in the tube on the pipe wall. The experimental results show that the relationships between the flow rate and the demodulated phase changes, in both a whole frequency region and in a sensitive-response frequency region, fit the quadratic equation well, with a max R² of 0.997, which is consistent with the theoretical simulation results. The detectable flow rate is from 0.73 m³/h to 2.48 m³/h. The experiments verify the feasibility of DAS system flow monitoring and provide technical support for the practical application of the downhole flow measurement.