Analysis on prevention process adaptability of shale gas wellhead hydrate

In view of the high water content during the drainage production period of shale gas wells, the wellhead and downstream pipelines may be blocked. The HYSYS software is used to predict the hydrate formation of shale gas wellheads under multiple working conditions and it is found that when the well is reopened after shutting-in at the initial stage of normal production and high gas-water ratio, hydrates may appear. The adaptability of the alcohol injection technology and heating process currently used in shale gas fields is analyzed. It is found that the total investment cost of the heating process is slightly higher than that of the alcohol injection process, but the treatment volume range of the heating process was larger and the prevention effect was more significant. For resumption of production after shutting-in during production and high gas-water ratio, a water jacket heating furnace and a mobile alcohol injection skid with a filling volume of 45 kg/d can be considered for use. In the later stage of production, after removing the water jacket heating furnace skid, some wellheads are at risk of hydrate formation under low ambient temperature conditions in winter. The hydrate inhibitor filling port can be reserved in the cluster well group skid-mounted device. The research results provide technical support for hydrate prevention plans of shale gas wells.