页岩气井口水合物预防工艺适应性分析

Analysis on prevention process adaptability of shale gas wellhead hydrate

关键词:  页岩气井  水合物  HYSYS软件  注醇工艺  加热工艺

Key words:  shale gas well  hydrate  HYSYS software  alcohol injection process  heating process

摘要:

针对页岩气井排液生产期内的水含量很高,井口及下游管线可能出现堵塞现象,采用HYSYS软件对页岩气井口多工况进行水合物形成预测,发现在正常生产初期关井后重新开井和高气水比时,可能会出现水合物。并对目前页岩气田采用的注醇工艺和加热工艺进行了适应性分析。结果 发现,加热工艺的总投资成本略高于注醇工艺,但是加热工艺的处理量范围较大,并且预防效果较为显著。对生产期间关井后复产和高气水比时,可考虑水套加热炉和加注量为45 kg/d的移动注醇撬进行搭配使用。在生产后期,拆除水套加热炉撬后,在冬季环境温度较低的条件下,部分井口存在水合物形成风险,可在丛式井组撬装装置预留水合物抑制剂加注口。研究结果为页岩气井制定水合物预防方案提供了技术支撑。 

Abstract:

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.