DOWN-HOLE LIQUID LEVEL CONTROL FOR HYDROCARBON WELLS

• US 20100038078A1
• Filed: 08/13/2009
• Published: 02/18/2010
• Est. Priority Date: 08/15/2008
• Status: Active Grant

• Current Assignee: CNX Gas Company LLC (CNX Gas Corporation)
• Original Assignee: CNX Gas Company LLC (CNX Gas Corporation)
• Inventors: Fink, Joseph M.
• Granted Patent: US 8,235,111 B2
• Time in Patent Office: Days
• US Class Current: 166/250.150
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: E21B 43/13 specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds
• CPC Class Codes: E21B 47/008 Monitoring of down-hole pump systems, e.g. for the detection of "pumped-off" conditions
• CPC Class Codes: E21B 47/047 Liquid level measuring depth or liquid level using radioactive markers E21B47/053
• CPC Class Codes: F04B 49/025 by means of floats
• CPC Class Codes: F04D 13/08 for submerged use

Abstract

This invention provides for an apparatus that controls a liquid level down-hole of a hydrocarbon producing well by physically monitoring the liquid level down-hole having a down-hole liquid level measurer and a signal device connected to the liquid level measurer that causes a pump to adjust its current liquid output based on the liquid level down-hole as measured by the down-hole liquid level measurer.

Claims

1. An apparatus that controls a liquid level down-hole of a hydrocarbon producing well by monitoring the liquid level down-hole in the well comprising:

(a) a down-hole liquid level measurer; and

(b) a signal device connected to the liquid level measurer that causes a pump to adjust its current liquid output based on the liquid level down-hole as measured by the down-hole liquid level measurer.

2. An apparatus as recited in claim 1 wherein monitoring the liquid level down-hole in the well is done physically.

3. An apparatus as recited in claim 1 wherein the liquid level measurer comprises:

(a) a support structure; and

(b) a float connected to the support structure so that it is able to move vertically up and down the support structure and its position is determined by the liquid level down-hole.

4. An apparatus as recited in claim 3 wherein the signal device comprises:

(a) a top target connected to the float;

(b) a bottom target connected to the float;

(c) an upper sensing device connected to an upper support structure so that when the liquid level down-hole causes the float to rise vertically, the top target engages the upper sensing device thereby initiating an increase in the amount of liquid removed from the well; and

(d) a lower sensing device connected to a lower support structure so that when the liquid level down-hole causes the float to descend vertically, the lower target engages the lower sensing device thereby initiating a decrease in the amount of liquid removed from the well.

5. An apparatus as recited in claim 3 wherein the support structure is a guide that allows the float to move with a surface of the liquid level within the guide.

6. A method of producing natural gas from a well comprising:

(a) providing a well that produces natural gas and a liquid;

(b) providing a pump for removing the liquid from the well;

(c) monitoring a liquid level down-hole in the well;

(d) adjusting the pump to alter the output of liquid from the well and thereby controlling the liquid level down-hole based on the physical monitoring of the liquid level down-hole in the well; and

(e) producing natural gas from the well.

7. A method as recited in claim 6 wherein monitoring the liquid level down-hole in the well is done physically.

8. A method as recited in claim 6 wherein:

(a) the monitoring is accomplished by a liquid level measurer; and

(b) adjusting the pump is done by a signal device connected to the liquid level measurer.

9. A method as recited in claim 8 wherein the signal device comprises:

(a) a top target connected to the float;

(b) a bottom target connected to the float;

(c) an upper sensing device connected to an upper support structure so that when the liquid level down-hole causes the float to rise vertically the top target engages the upper sensing device thereby initiating an increase in the amount of liquid removed from the well; and

(d) a lower sensing device connected to a lower support structure so that when the liquid level down-hole causes the float to descend vertically the lower target engages the lower sensing device thereby initiating a decrease in the amount of liquid removed from the well.

10. A method as recited in claim 8 wherein the liquid level measurer comprises:

(a) a support structure; and

(b) a float connected to the support structure so that it is able to move vertically up and down the support structure and its position is determined by the liquid level down-hole.

11. A method for removing oil from a well comprising:

(a) providing a well that produces oil;

(b) providing a pump for removing the oil from the well;

(c) monitoring an oil level down-hole in the well;

(d) adjusting the pump to alter the output of oil from the well and thereby controlling the oil level down-hole based on the physical monitoring of the oil level down-hole in the well; and

(e) producing the oil from the well.

12. A method as recited in claim 11 wherein monitoring the oil level down-hole in the well is done physically.

13. A method as recited in claim 11 wherein:

(a) the monitoring is accomplished by a liquid level measurer; and

(b) adjusting the pump is done by a signal device connected to the liquid level measurer.

14. A method as recited in claim 13 wherein the signal device comprises:

(a) a top target connected to the float;

(b) a bottom target connected to the float;

(c) an upper sensing device connected to an upper support structure so that when the oil level down-hole causes the float to rise vertically the top target engages the upper sensing device thereby initiating an increase in the amount of oil removed from the well; and

(d) a lower sensing device connected to a lower support structure so that when the oil level down-hole causes the float to descend vertically the lower target engages the lower sensing device thereby initiating a decrease in the amount of oil removed from the well.

15. A method as recited in claim 13 wherein the liquid level measurer comprises:

(a) a support structure; and

(b) a float connected to the support structure so that it is able to move vertically up and down the support structure and its position is determined by the oil level down-hole.

16. An apparatus that controls the liquid level down-hole of a hydrocarbon producing well comprising:

(a) a down-hole sensor that determines a pressure above a pump in a hydrocarbon producing well;

(b) a surface pressure sensor that determines the gas within the well bore; and

(c) a controller connected to the down-hole pressure sensor, the surface pressure sensor, and the pump wherein the controller calculates and controls the liquid level down-hole by using the down-hole pressure reading and the surface pressure reading to determine the liquid level down-hole and adjusting the pump so that the liquid level down-hole is maintained at a predetermined level.

17. An apparatus as recited in claim 16 wherein the algorithm to calculate the liquid level down-hole is:

$\frac{y-x}{\mathrm{sw}}=z$

where x=surface pressure;

y=down-hole pressure;

z=liquid level; and

sw=specific weight.