油田进入开发中后期，采出液含水率急剧上升，如何降低含水率并提高采收率是开发后期需要解决的首要问题。井下油水分离技术利用水力旋流技术、重力分离技术或其他油水分离工艺实现在井下对采出液进行预分离，从而采出较低含水率的油水混合液，此项技术对于高含水油田具有很大应用前景。通过对井下油水分离装置的研究现状进行简要分析与总结，并指出目前井下油水分离装置存在的问题与挑战，同时做出展望，为其发展提供一定的参考。

When the oilfield enters the middle and late stages of development, the moisture content of the produced liquid rises sharply. The primary problem that needs to be solved in the later stage of development is how to reduce the water content and improve the recovery rate. Hydrocyclone technology, gravity separation technology or other oil-water separation processes are used for downhole oil-water separation to achieve pre-separation of the moisture liquid downhole, so as to produce a lower water-water mixture, which has great application prospects for high water-cut oilfields. Through the brief analysis and summary of the research status of downhole oil-water separation device, the problems and challenges of the current downhole oil-water separation device were pointed out, and the prospect was made to provide a certain reference for its development.