Detection of transient gas-liquid flow structures in horizontal shale gas well using wire-mesh sensor

摘要

Gas-liquid two-phase flows in shale gas well are characterized by extremely unstable motions. In this study, we proposed a new conductance wire-mesh sensor (WMS) operated in a mode of sinusoidal excitation, and designed a flow loop with multi-nozzle gas inlet to mimic the transient gas-liquid flows in horizontal shale gas well. The designed WMS was successively mounted at non-stationary and stationary sections along the pipe line to detect the transient flow structures. Flow pattern transitions at non-stationary and stationary sections are investigated according to the WMS flow visualizations. Notably, local structures of non-stationary gas-liquid flows are detected using the WMS. The results indicate that plug flows at non-stationary pipe section are characterized by wave bridge and pseudo slug, and local evolution characteristics of the wave bridge and the pseudo slug can dominate the initiation of slug flow.