| 摘要 |
A reciprocated pump positioned at the lower end of a string of tubing in a bore hole that provides a passageway for moving formation fluid to the earth's surface, including a pump barrel supported in communication with the tubing and a standing valve at the lower end thereof providing a first passageway through which formation fluid flows into the pump barrel, the pump barrel having an intermediate vent port providing a second entry passageway, and a tubular plunger reciprocated within the barrel and having an upper and a lower portion with a plurality of non-metallic seal rings separated by metallic spacers received on the plunger upper portion and configured to support a column of formation fluid within the tubing to substantially isolate the portion of the barrel below the non-metallic seal rings from the tubing pressure to thereby allow formation fluid to move into the pump barrel. |
