| 摘要 |
The invention relates to the oil-producing industry and can be used for extracting oil in the presence of high sand content in the formation fluid and large well curvature. The downhole pump assembly comprises a pump, installed in a pipe string, with a movable working body, and an inlet/outlet valve connected to a wellhead drive by means of a bypass channel for supplying a drive medium. According to the invention, the movable working body is in the form of a buffer fluid located in the bottom part of the pump chamber of the pump housing below an inlet valve, forming a hydro-seal and being able to interact with the pumped fluid which enters the pump chamber through a lateral aperture in the pump housing and through the inlet valve. The bypass channel is in the form of a flexible pipe located externally or internally. The wellhead drive is in the form of a hydraulic pump or a gas compressor. Mineral oil, synthetic oil, light hydrocarbons, or liquids with low specific weight are used as the drive medium, and mercury, a solution of zinc bromide and calcium bromide, a liquid with high specific weight, or a sequence of the above is used as the movable working body. When using a gas compressor, inert gas is used as an additional drive medium. One drive works with a plurality of wells, and the flexible pipe additionally contains electric wires, a warming cable, and a hydro-channel. |
