Patent ID: 6027313
Filing Date: 2000-02-22
Classification: E21B

Abstract:
A fluid delivery system comprising:a) a pump;b) a fluid conduit having an upper end operatively connected to the pump and a lower end having a fluid inlet in communication with a fluid supply, the upper end of the fluid conduit being located higher than the lower end;c) a regulated gas inlet comprising a gas supply maintained at a first pressure; a pressure monitoring conduit in fluid communication with the fluid conduit at an intermediate location disposed between said upper and lower ends; a gas delivery conduit in fluid communication with the fluid conduit at a location between the upper end and the intermediate location; and a pressure-responsive valve operatively connected to the pressure monitoring conduit and moving between a closed position wherein flow of gas from the gas supply into the fluid conduit through the gas delivery conduit is restricted, and at least one open position wherein gas from the gas supply is delivered to the fluid conduit through the gas supply conduit, the valve being normally biased toward the closed position but moving to the open position when pressure within the pressure monitoring conduit is below the first pressure by more than a predetermined level.