| 摘要 |
The invention provides apparatus for producing well fluids from an oil bearing formation penetrated by a well including a tubing string forming a production flow path for production fluids between the earth's surface and a location in the well suitable for receiving well production fluids, a power tubing parallel to the production tubing and connected to the flow path of the production tubing, a pump barrel formed in the power tubing, and a lubricating plunger in the pump barrel forming an annulus therewith and having ports to permit flow of lubricating fluids from the lubricating plunger into the annulus. The apparatus is provided with means for providing lubrication fluid to the lubricating plunger.
|
