A Water Volume Fraction Measurement Method Based on Flow Regime Insensitivity-Microwave Resonant Cavity Sensor (FRI-MRCS)

In the process of natural gas exploitation, the complex pipe network coupled with changes in pressure and temperature can result in a variety of flow regimes, complicating the use of microwave technology for water content measurement. To overcome this challenge, this study introduces a flow regime insensitivity-microwave resonant cavity sensor (FRI-MRCS). We achieved flow uniformity and regularity by converting the pipeline into a Venturi structure and introducing a swirler within the Venturi contraction section. This design induced a spiral annular flow in the gas–water two-phase flow, which mitigates the influence of the gas–water distribution on the water content measurement. The flow regime modified ability of the swirler is demonstrated by FLUENT simulation. The water content measurement characteristics of FRI-MRCS are investigated through experiments, and the water volume fraction prediction model (0%–5%) is established. The confidence probability of relative error within ±10% is 90.6%. The results show that the FRI-MRCS proposed in this study provides a reliable and effective solution for the measurement of water content in the oil and gas industry.