The hydraulic feedback subsurface pump with double plungers, which is developed on the basis of conventional subsurface pumps is a special pump for viscous oil recovery.

• 双柱塞反馈式抽油泵是在改进常规抽油泵结构的基础上发展起来的一种适于高粘原油开采的特殊抽油泵。这种泵在使用中柱塞损坏相当严重，极大地影响了油井的正常生产。