Abstract: A gas pump system for producing a well has production tubing, a chamber to collect liquid from the well, a check valve to allow well liquids to flow into the chamber and to check flow out of the chamber, a dip tube in communication with the production tubing and the chamber, a check valve to allow liquid to flow up the dip tube into the production tubing and to check liquid flowing down the dip tube, a gas supply line to convey gas into the chamber, a hydraulic valve controlling flow through the gas supply line, a gas vent line to vent gas from the chamber, a hydraulic valve controlling flow through the gas vent line, a control line communicating with one or both of the gas supply valve and the gas vent valve, and a shut-off valve in the well controlling flow through the control line.

Abstract: A gas lift system for oil and gas wells has a gas pump. The gas pump comprises production tubing, a chamber, a dip tube, check valves, a gas supply line and control valve, a gas vent line and control valve, and a fluid control line. Liquid is pumped to the surface by allowing it to collect in the chamber and then forcing it out of the chamber with high-pressure gas. The gas supply and vent valves preferably are controlled by a single pressure control line. The system preferably included retrievable valves that may be installed through the production tubing to provide a life-of-the-well gas lift system.

Abstract: A method of unloading and producing liquids from a well uses a plurality of gas injection valves installed on a production tubing. The injection valves are controlled by pressure signals transmitted through a single fluid control line. A first pressure signal is applied to the control line to open the plurality of injection valves. Gas is pumped into the annulus at an injection pressure until a first pressure drop occurs in the injection pressure, the first pressure drop being indicative of gas flowing through a first, upper one of the injection valves. Pumping of gas is continued until a second pressure drop occurs in the injection pressure, the second pressure drop being indicative of gas flowing through a second, lower one of the injection valves. A second, lower pressure signal then is applied to close the first injection valve while leaving the second injection valve open.

Abstract: A gas control valve has a valve housing, a gas flowpath, a piston, a valve seat, a valve body, an actuating chamber, and a stack of Belleville washers. The valve housing has a gas inlet, a gas outlet, and a control fluid inlet. The gas flowpath runs from the gas inlet to the gas outlet. The piston reciprocates away from and towards a normal position. The valve body is coupled to the piston and is adapted to selectively seat on the valve seat to open and shut the gas flowpath. The actuating chamber communicates with the control fluid inlet. The washer stack is under compression to bias the piston in the normal position. The piston is responsive to fluid pressure in the actuating chamber and the washer stack so that the valve may be selectively opened and closed by sequentially increasing and decreasing pressure in the actuating chamber.

Abstract: A gas lift system for oil and gas wells has a gas pump. The gas pump comprises production tubing, a chamber, a dip tube, check valves, a gas supply line and control valve, a gas vent line and control valve, and a fluid control line. Liquid is pumped to the surface by allowing it to collect in the chamber and then forcing it out of the chamber with high-pressure gas. The gas supply and vent valves preferably are controlled by a single pressure control line. The system preferably included retrievable valves that may be installed through the production tubing to provide a life-of-the-well gas lift system.