Integrated downhole throttling and atomization drainage technology: Research and application in high-pressure water-producing gas wells

High-pressure, low-yield gas wells in the Songliao Basin suffer from bottom-hole liquid loading and hydrate blockage as formation water production increases. Conventional downhole throttling lacks active liquid drainage, and methanol injection is costly and only partially effective. To overcome these limitations, this study develops an integrated downhole throttling-atomization-drainage device. The structure features a spiral channel for cyclonic gas–liquid separation and a downstream atomizing nozzle with a crushing unit for secondary atomization. Laboratory high-speed imaging experiments compare the proposed device with a conventional nozzle without a spiral element. Results show that the conventional nozzle produces a liquid column core and subsequent wall film accumulation, whereas the spiral atomizing nozzle generates a fully dispersed spray field without observable wall wetting. Field application in a Songliao Basin well, with the device installed at 1503 m and a 4 mm orifice, was conducted without methanol injection. After installation, wellhead tubing pressure decreased from 13 to 4.5 MPa, daily water production increased from 1.0 to 2.4 m3, and no hydrate formation was observed. These results demonstrate that the integrated downhole throttling-atomization-drainage technology effectively mitigates both hydrate blockage and bottom-hole liquid loading in high-water-producing gas wells.