Method and apparatus for pumping wells with a sealing fluid displacement device

摘要

Liquid is lifted from a well by a fluid displacement device which moves within a production tubing and maintains a seal against the production tubing during movement. The fluid displacement device is moved up and down within the production tubing between the well bottom and the earth surface by applying gas to create opposite relative pressure differentials across the fluid displacement device. Preferably the pressure differentials are obtained from gas supplied from the well at natural formation pressure.