Low Rate Gas Injection System

• US 20100051288A1
• Filed: 09/03/2008
• Published: 03/04/2010
• Est. Priority Date: 09/03/2008
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Gaudette, Sean L.
• Granted Patent: US 7,793,727 B2
• Time in Patent Office: Days
• US Class Current: 166/372
• CPC Class Codes: E21B 2200/05 Flapper valves
• CPC Class Codes: E21B 34/08 responsive to flow or pressure of the fluid obtained E21B34/10 takes precedence
• CPC Class Codes: E21B 43/13 specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds

Abstract

A dewatering device is provided that can be inserted concentrically within the production tubing string of a natural gas-producing wellbore. The dewatering device includes a pressure-isolating chamber that is provided with a fluid inlet valve and a fluid outlet valve and associated gas lift valves. Compressed gas and soap are used to form a foamy liquid mixture that is lifted out of the chamber.

Claims

1. A dewatering device for removing water from a natural gas well, the device comprising:

a housing defining a chamber with a fluid inlet valve and a fluid outlet valve;

the fluid inlet valve being operable between an open position, wherein water within the natural gas well can enter the chamber, and a closed position, wherein water is blocked from entering the chamber;

the fluid outlet valve being in communication with a water removal conduit and being operable between a closed position, wherein fluid within the chamber cannot be communicated from the chamber to the water removal conduit, and an open position, wherein fluid within the chamber can be communicated from the chamber to the water removal conduit;

a soap supply operably interconnected with the housing to deliver soap into the chamber to intermix with water entering the chamber through the fluid inlet valve; and

a gas supply operably interconnected with the housing to deliver a compressed gas into the chamber and agitate the soap and water into a foamy liquid mixture.

2. The dewatering device of claim 1 further comprising a gas lift valve located within the chamber and operably associated with the gas supply for delivery of gas within the chamber, the gas lift valve being operable between open and closed positions.

3. The dewatering device of claim 1 further comprising a gas lift valve located within a water removal conduit proximate the fluid outlet valve, the gas lift valve being operable between open and closed positions.

4. The dewatering device of claim 3 wherein the gas lift valve is located outside of the chamber.

5. The dewatering device of claim 1 further comprising:

a first gas lift valve located within chamber and operably associated with the gas supply for delivery of gas within the chamber, the gas lift valve being operable between open and closed positions; and

a second gas lift valve located within a water removal conduit proximate the fluid outlet valve, the gas lift valve being operable between open and closed positions.

6. The dewatering device of claim 5 further comprising a controller operably interconnected with the first and second gas lift valve to operate the gas lift valves in accordance with a predetermined scheme.

7. The dewatering device of claim 1 further comprising a controller operably interconnected with the fluid inlet valve and fluid outlet valves to operate the valves in accordance with a predetermined scheme.

8. The dewatering device of claim 7 further comprising a liquid level sensor operable to determine the level of liquid within the chamber and being operably interconnected with the controller to provide a signal representative of said level of liquid to the controller.

9. The dewatering device of claim 8 wherein the liquid level sensor comprises a float valve.

10. A system for removing water from a natural gas well, the system comprising:

a housing interconnected with a tool string which defines a water removal conduit, the housing defining a chamber with a fluid inlet valve and a fluid outlet valve;

the fluid inlet valve being operable between an open position, wherein water within the natural gas well can enter the chamber, and a closed position, wherein water is blocked from entering the chamber;

the fluid outlet valve being in communication with the water removal conduit and being operable between a closed position, wherein fluid within the chamber cannot be communicated from the chamber to the water removal conduit, and an open position, wherein fluid within the chamber can be communicated from the chamber to the water removal conduit;

a soap supply operably interconnected with the housing to deliver soap into the chamber to intermix with water entering the chamber through the fluid inlet valve; and

a gas supply operably interconnected with the housing to deliver a compressed gas into the chamber and agitate the soap and water into a foamy liquid mixture.

11. The system of claim 10 further comprising:

a first gas lift valve located within chamber and operably associated with the gas supply for delivery of gas within the chamber, the gas lift valve being operable between open and closed positions; and

a second gas lift valve located within a water removal conduit proximate the fluid outlet valve, the gas lift valve being operable between open and closed positions.

12. The system of claim 10 further comprising a gas lift valve located within the chamber and operably associated with the gas supply for delivery of gas within the chamber, the gas lift valve being operable between open and closed positions.

13. The system of claim 11 further comprising a controller operably interconnected with the first and second gas lift valve to operate the gas lift valves in accordance with a predetermined scheme.

14. The system of claim 10 further comprising a controller operably interconnected with the fluid inlet valve and fluid outlet valves to operate the valves in accordance with a predetermined scheme.

15. A method for removing water from a natural gas well comprising the steps of:

disposing a dewatering device into the well on a tool string having a water removal conduit, the dewatering device comprising;

a housing defining a pressure-isolation chamber; and

a fluid outlet valve operable between open positions to selectively flow fluid from the chamber to the water removal conduit;

flowing water from the well into the chamber;

flowing soap into the chamber to mix with the water to form a foamy mixture; and

opening the fluid outlet valve to flow the foamy mixture into the water removal conduit.

16. The method of claim 15 further comprising the step of flowing a compressed gas into the chamber to mix the water and soap into a foamy mixture.

17. The method of claim 15 further comprising the step of flowing a compressed gas into the water removal conduit after opening the fluid outlet valve to help flow the foamy mixture along the water removal conduit.

18. A dewatering device for removing water from a natural gas well, the device comprising:

a housing defining a chamber with a fluid inlet valve and a fluid outlet valve;

the fluid inlet valve being operable between an open position, wherein water within the natural gas well can enter the chamber, and a closed position, wherein water is blocked from entering the chamber;

the fluid outlet valve being in communication with a water removal conduit and being operable between a closed position, wherein fluid within the chamber cannot be communicated from the chamber to the water removal conduit, and an open position, to wherein fluid within the chamber can be communicated from the chamber to the water removal conduit;

a gas supply operably interconnected with the housing to deliver a compressed gas into the chamber and agitate the water.

19. The dewatering device of claim 18 further comprising a soap supply operably interconnected with the housing to deliver soap into the chamber to intermix with water entering the chamber through the fluid inlet valve.