Methane extraction method and apparatus using high-energy diode lasers or diode-pumped solid state lasers

Abstract

A method and apparatus for extracting methane gas from methane hydrate. The method includes heating the methane hydrate with a laser apparatus. The laser apparatus includes a diode laser or a solid state laser that is pumped with a diode laser. The laser is guided to a working end of a tool with a fiber optic bundle. The tool is guided to heat the methane hydrate with the laser, which emanates from a beam expander at the working end of the tool. The tool can be modified for removing obstructions of methane hydrate in pipelines. Also, the tool can be modified for extracting methane from mined methane hydrate, which is in a container. The characteristics of diode lasers or diode-pumped solid state lasers such as efficiency, size, nature of operation, environmental impact and durability, make methane gas extraction from methane hydrate economically feasible.

1 . A method of extracting methane gas from methane hydrate comprising heating the methane hydrate with a laser beam of a diode laser or a solid state laser that is pumped with a diode laser to release methane gas from the methane hydrate. 
   
   
       2 . The method of  claim 1  including;
 guiding the laser beam with an optic fiber to and end of a tool; and   placing the end of the tool in the methane hydrate.   
   
   
       3 . The method of  claim 1  including expanding the laser beam with a beam expander at the end of the tool. 
   
   
       4 . The method of  claim 1 , wherein the laser is a diode laser. 
   
   
       5 . The method of  claim 1  including operating the laser in a pulsed mode. 
   
   
       6 . The method of  claim 1  including operating the laser in a continuous mode. 
   
   
       7 . A method of removing a methane hydrate obstruction in a gas pipeline comprising heating the methane hydrate with a laser beam of a diode laser or a solid state laser that is pumped with a diode laser to change the phase of the obstruction. 
   
   
       8 . The method of  claim 7  including:
 providing a tool for supporting an optic fiber; and   directing the laser beam with an optic fiber toward a working end of the tool; and   guiding the tool to direct the laser beam toward the obstruction.   
   
   
       9 . A method of boring through a methane hydrate formation to access a natural gas pocket that is located beneath the methane hydrate formation comprising:
 forming a bore hole through the methane hydrate with a laser beam of a diode laser or a laser that is pumped with a diode laser; and   placing a drill in the bore hole to drill beneath the methane hydrate formation to access the natural gas pocket.   
   
   
       10 . An apparatus for extracting methane from methane hydrate comprising:
 an extraction tool;   a diode laser or a laser that is pumped with a diode laser; and   an optic fiber for leading a laser beam generated by the laser to a working end of the extraction tool.   
   
   
       11 . The apparatus of  claim 10  further comprising a conduit for conducting extracted methane from a methane formation toward a proximal end of the extraction tool. 
   
   
       12 . The apparatus of  claim 10  further comprising a beam expander for expanding the laser beam before the laser beam strikes the methane hydrate. 
   
   
       13 . The apparatus of  claim 12 , wherein the beam expander includes apparatus for forming an air curtain adjacent to a lens of the beam expander so that the lens is self-cleaning. 
   
   
       14 . The apparatus of  claim 13 , wherein the extraction tool includes an air passage for delivering air to the apparatus for forming an air curtain. 
   
   
       15 . The apparatus of  claim 10 , wherein the laser is a diode laser. 
   
   
       16 . The apparatus of  claim 10 , wherein the extraction tool includes a water cooling passage for cooling the optic fiber. 
   
   
       17 . The apparatus of  claim 10 , wherein the extraction tool is supported by a platform, which carries the laser.