Controllable gas-lift well and valve

A controllable gas-lift well, comprising:

• a wellbore extending into the earth from the surface;
• a production tubing positioned and longitudinally extending within the wellbore;
• a gas-lift valve coupled to the production tubing in the wellbore, the valve being electrically adjustable to regulate the fluid flow between an interior and an exterior of the tubing, wherein the valve is powered and controlled by using the production tubing as an electrical conductor;
• and
• a lower impedance device coupled to the tubing, the controllable gas-lift valve being electrically coupled to the tubing.

A controllable gas-lift well, comprising:

• a wellbore extending from a first location to a second location;
• a casing positioned and longitudinally extending within the wellbore;
• a production tubing string positioned and longitudinally extending within the casing;
• a controllable gas-lift valve coupled to the production tubing string between the first location and the second location, the valve being electrically adjustable to regulate the fluid flow between an interior and an exterior of the tubing string, the valve being coupled to receive electrical signals by using the tubing string as a first conductor and the casing as a second conductor;
• and
• a lower impedance device coupled to the tubing, the controllable gas-lift valve being electrically coupled to the tubing above the lower impedance device.

A method of operating a gas-lift well comprising the steps of:

• providing an upper impedance device effective to act as impedance to current flow past the upper impedance device;
• inputting an AC signal to a production tubing string below the upper impedance device, the production tubing string positioned within and longitudinally extending along a borehole of the well, the borehole extending from a surface of the well to a downhole location;
• and
• operating a gas-lift valve coupled to the production tubing string using said input AC signal to said production tubing string to control the amount of lift gas flowing from outside the production tubing string to the inside of the production tubing string to assist in lifting oil from said downhole location towards the surface.

A gas-lift valve adapted to be coupling to a production tubing string, the gas-lift valve comprising:

• a housing having an inlet and an outlet;
• a modem adapted to be electrically coupled to the tubing string for receiving an AC communication signal from the production tubing string;
• an upper impedance device effective to act as impedance to current flow past the upper impedance device;
• a power supply adapted to be electrically coupled to the production tubing string for receiving power input to the production tubing string below the upper impedance device;
• a mechanical valve head positioned within the housing and being adjustable for metering the amount of fluid flow between the inlet and outlet of the housing;
• and
• a controller operably connected to the modem, the valve head, and the power supply for adjusting the valve head in response to an AC communication signal received by the modem along the production tubing string.