Surface control of gas lift valves

Abstract

This invention is a method of surface control of gas lift valves through a pneumatic tube control line connecting high-pressure charging gas at surface to the valve bellows/dome of one or more valves positioned on the production tubing within an oil, gas, or water supply well. The control line transmits pressure to close the valve or relieves pressure to open the valve. This invention eliminates the requirement of pressure charging and sealing the gas lift valve bellows/dome at the shop facility as a pre-installation condition and eliminates estimating valve temperature at wellbore conditions to correctly set a valve charge pressure in a sealed chamber. One control line can be connected to multiple valves or, as an option, individual lines to each valve can be implemented. This invention applies to injection pressure operated (IPO) or production pressure operated (PPO) gas lift valves and tubing retrievable (conventional) or side pocket mandrels.

1 . A method to close or to open gas lift valves from the surface using a pneumatic tube control line to convey charge gas (natural gas, nitrogen, carbon dioxide, air, or other fluid) to the bellows/dome of the valve; this control method is applied to wells with one or multiple gas lift valves positioned on the tubing at depths desired to displace control (kill) fluids from the casing/tubing annulus and inside the tubing by enabling gas to pass from the annulus through an open valve to the tubing and circulating the fluid to the treating facility; surface control revealed by this disclosure enables the valve to be closed by raising control line charge pressure at the surface whereby the multiple valves are closed in sequence as surface charge gas pressure is increased; valves can be opened by reducing charge pressure at the surface; an option is a control line to each individual valve instead of one control line connected to all valves. 
     
     
         2 . The method of  claim 1  is applied to tubing retrievable gas lift valves by directly connecting the charge gas pneumatic tube control line to the bellows/dome of any prior art gas lift valve from any manufacturer; the control line connects to the tail plug position of the gas lift valve, which does not contain a dill core (Schrader) valve, whereby increasing charge pressure inside the bellows/dome to close the valve and reducing charge pressure to open the valve; each valve is closed in sequence, from top to a depth near the packer, as control line charge pressure is raised whereby each valve at a deeper installation depth requires additional pressure; as control line pressure is reduced, the valves open in sequence from a depth near the packer to the top; an option is an orifice installed at the deepest point near the packer without a control line connection since it cannot close. 
     
     
         3 . The method of  claim 1  to close or to open gas lift valves from the surface using a pneumatic tube control line to convey charge gas (natural gas, nitrogen, carbon dioxide, air, or other fluid) to the gas lift valve bellows/dome is modified for side pocket mandrels with wireline retrievable gas lift valves; the control line connects to the side pocket mandrel which transmits the charge pressure to the wireline retrievable gas lift valve; this disclosure requires seals above and below passageways on the wireline retrievable valve that access the bellows/dome area for application of charge gas from the control line connected to the side pocket mandrel whereby pressure is transmitted and contained within the seals of the wireline gas lift valve to the bellows/dome area to close the valve; reduced charge pressure will open the valve; the tail plug is installed but the dill core (Schrader) valve is not required. 
     
     
         4 .  Claim 3  modifies the upper section of the wireline retrievable gas lift valve that includes the bellows/dome to include slots that transmit pressure from the control line attached to the side pocket mandrel to the dome of the valve, but the lower section can be any prior art gas lift valve from any manufacturer. 
     
     
         5 .  Claim 1  and  claim 3  eliminate the requirement to pull valves from the well to reset a sealed valve charge pressure if a different setting is desired, because this invention provides surface control of charge pressure;  claim 1  and  claim 3  eliminate the need for a valve temperature at valve depth since this invention does not have a sealed chamber where pressure is dependent on the temperature; with this disclosure, charge pressure at surface can be adjusted to close or to open a gas lift valve when transmitted through the pneumatic tube control line to each valve.