Methods, systems, and devices for extracting a gas from a subsurface stratum

Abstract

A fluid flow control device having at least one bypass valve that is actuated in response to the movement of an annular body housed in the device. The annular body may be housed in a cylindrical housing and be a buoyant or non-buoyant body, such as a non-buoyant annular ring. The movement of the annular body in the cylindrical housing actuates the one or more bypass valves. Flow through the bypass valves returns the fluid to its source, for example, to an aquifer while maintaining a desired liquid level. The fluid flow control device can provide an effective means for regulating the elevation of subsurface fluids, for example, ground water, to enhance the efficiency of gas extraction from subsurface strata, for example, the extraction of methane from water and methane containing coal beds. Systems and methods of extracting gases from subsurface strata are also provided.

1 . A method of extracting a gas from a subsurface stratum containing the gas and a liquid, the method comprising:
 providing a first conduit from a surface whereby the liquid produces a liquid level in the first conduit;   inserting a pumping device into the first conduit, the pumping device having an inlet below the liquid level and an outlet;   inserting a second conduit into the first conduit, the second conduit providing a fluid path from the outlet of the pump to the surface;   pumping the liquid from the subsurface stratum to the surface through the second conduit; and   maintaining the liquid level in the first conduit whereby at least some of the gas escapes from the subsurface stratum and passes through the first conduit to the surface.   
   
   
       2 . The method as recited in  claim 1 , wherein the gas comprises methane, the liquid comprises water, and the subsurface stratum comprises a coal bed. 
   
   
       3 . The method as recited in  claim 1 , wherein maintaining the liquid level in the first conduit comprises diverting at least some liquid pumped by the pump from the second conduit to the first conduit. 
   
   
       4 . The method as recited in  claim 1 , wherein maintaining the liquid level in the first conduit comprises monitoring the liquid level at a desired level and diverting at least some liquid pumped by the pump from the second conduit to the first conduit when the liquid level deviates from the desired level. 
   
   
       5 . The method as recited in  claim 1 , wherein maintaining the liquid level comprises providing a body in the first conduit below the liquid level, and providing means to actuate at least one valve in response to the movement of the body. 
   
   
       6 . The method as recited in  claim 5 , wherein the body comprises a buoyant body. 
   
   
       7 . The method as recited in  claim 5 , wherein maintaining the liquid level further comprises providing the body in a housing, the housing being in fluid communication with the first conduit. 
   
   
       8 . The method as recited in  claim 1 , wherein inserting a first conduit further comprises providing a sealing casing for the first conduit. 
   
   
       9 . The method as recited in  claim 1 , wherein inserting a pumping device into the first conduit comprises inserting the pump at a position within the subsurface stratum 
   
   
       10 . A system for extracting a gas from a subsurface stratum containing the gas and a liquid, the system comprising:
 a first conduit directed from a surface to the stratum whereby the liquid produces a liquid level in the first conduit;   a pumping device positioned below the liquid level, the pumping device having an inlet below the liquid level and an outlet;   a second conduit positioned inside the first conduit, the second conduit providing a fluid path from the outlet of the pumping device to the surface;   means for maintaining the liquid level in the first conduit whereby at least some of the gas escapes from the subsurface stratum and passes through the first conduit to the surface while pumping the liquid from the subsurface stratum to the surface through the second conduit.   
   
   
       11 . The system as recited in  claim 10 , wherein the means for maintaining the liquid level in the first conduit comprises at least one valve adapted to divert liquid from the second conduct to the first conduit. 
   
   
       12 . The system as recited in  claim 10 , wherein the system further comprises a device adapted to monitor the liquid level and means for diverting at least some liquid pumped by the pump from the second conduit to the first conduit when the liquid level deviates from a desired level. 
   
   
       13 . The system as recited in  claim 12 , wherein the device comprises a body positioned in the first conduit below the liquid level, and wherein the means for diverting the at least some liquid comprises means to actuate at least one valve in response to the movement of the body. 
   
   
       14 . The system as recited in  claim 13 , wherein the body comprises a buoyant body. 
   
   
       15 . The system as recited in  claim 13 , wherein the system further comprises a housing enclosing the body, the housing being in fluid communication with the first conduit. 
   
   
       16 . A system for extracting methane from a coal bed containing methane and water, the system comprising:
 a first conduit directed from a surface to the coal bed whereby the water produces a water level in the first conduit;   a pump positioned below the liquid level, the pump having an inlet below the water level and an outlet;   a second conduit positioned inside the first conduit, the second conduit providing a fluid path from the outlet of the pump to the surface; and   a flow diverting device having a housing, an inlet in fluid communication with the outlet of the pump, a first outlet in fluid communication with the second conduit, a second outlet in fluid communication with the first conduit, a body mounted for vertical displacement within the housing, and at least one valve adapted to control water flow through the second outlet;   wherein the at least one valve is adapted to operate in response to the movement of the body to maintain the water level in the first conduit whereby at least some of the methane escapes from the coal bed and passes through the first conduit to the surface while pumping the water from the coal bed to the surface through the second conduit.   
   
   
       17 . The system as recited in  claim 16 , wherein the flow diverting device further comprises a set of linkages interconnecting the body and the at least one valve. 
   
   
       18 . The system as recited in  claim 16 , wherein the system further comprises a wellhead. 
   
   
       19 . The system as recited in  claim 19 , wherein the wellhead is adapted to isolate the methane from the water. 
   
   
       20 . A flow regulating device comprising:
 a cylindrical housing having a first end and a second end, the cylindrical housing having at least one perforation;   an inlet chamber mounted to the first end of the housing, the inlet chamber having an inlet adapted to receive a flow of fluid;   a conduit passing from the first end of the housing to the second end of the housing, the conduit having an inlet adjacent the first end of the housing in fluid communication with the inlet chamber;   at least one valve in the first end of the cylindrical housing, the at least one valve adapted to vary fluid communication between the inlet chamber and the cylindrical housing;   an annular disk mounted for axial movement within the cylindrical housing; and   means for actuating the at least one valve in response to the axial movement of the annular disk;   wherein deflection of the annular disk causes the means for actuating to actuate the at least one valve and provide fluid communication between the inlet chamber and the cylindrical body wherein at least some of the fluid introduced to the inlet of the inlet chamber is allowed to flow into the cylindrical housing and out of the at least one perforations in the cylindrical housing.   
   
   
       21 . The device as recited in  claim 20 , wherein the annular disk comprises thickness of less then 3 inches. 
   
   
       22 . The device as recited in  claim 20 , wherein the annular disk comprises a non-buoyant annular disk. 
   
   
       23 . The device as recited in  claim 22 , wherein the non-buoyant annular disk comprises a solid annular disk. 
   
   
       24 . The device as recited in  claim 29 , wherein the means for actuating the at least one valve comprises at set of linkages. 
   
   
       25 . The device as recited in  claim 20 , wherein the at least one perforation in the cylindrical housing is positioned adjacent the first end of the cylindrical housing. 
   
   
       26 . A method for regulating the flow of a fluid, the method comprising:
 providing a flow regulating device comprising:
 a cylindrical housing having a first end and a second end, the cylindrical housing having at least one perforation; 
 an inlet chamber mounted to the first end of the housing, the inlet chamber having an inlet adapted to receive a flow of fluid; 
 a conduit passing from the first end of the housing to the second end of the housing, the conduit having an inlet adjacent the first end of the housing in fluid communication with the inlet chamber; 
 at least one valve in the first end of the cylindrical housing, the at least one valve adapted to vary fluid communication between the inlet chamber and the cylindrical housing; 
 an annular body mounted for axial movement within the cylindrical housing, the annular body having an axial surface; and 
 means for actuating the at least one valve in response to the movement of the annular body; 
   mounting a fluid pumping device to the inlet of the inlet chamber;   immersing the flow regulating device and the fluid pumping device in a fluid to provide a level of fluid above the annular body;   providing a gas overpressure to the surface of the level of the fluid;   pumping the fluid into the inlet chamber and through the conduit by means of the pumping device; and   when the fluid level decreases wherein the axial surface of the annular disk is exposed to the gas overpressure, allowing the annular body to deflect under the force of the gas overpressure to actuate the means for actuating and open the at least one valve and permit fluid to flow from the inlet chamber to the cylindrical housing wherein the flow through the conduit is reduced.   
   
   
       27 . The method as recited in  claim 26 , wherein immersing the flow regulating device and the fluid pumping device in a fluid comprises immersing the flow regulating device and the fluid pumping device in a fluid containing subsurface stratum. 
   
   
       28 . The method as recited in  claim 27 , wherein the subsurface stratum further comprises methane gas, and wherein providing a gas overpressure to the surface of the level of the fluid comprises providing a methane gas overpressure from subsurface stratum. 
   
   
       29 . The method as recited in  claim 26 , wherein the annular body comprises an annular disk.