Storing carbon dioxide and producing methane and geothermal energy from deep saline aquifiers

Abstract

A novel idea involving the coupling of CO 2 geological storage with methane and/or heat production (geothermal energy) from geopressured-geothermal aquifers is described herein. The production of energy from the extracted brine offsets the cost of capture, pressurization, and injection and the subsequent injection of brine containing carbon dioxide back into the aquifer. Calculations described in the present invention indicate that this offset would reduce the cost of carbon capture and sequestration (CCS) to a point that CCS could survive in a competitive market environment without subsidies or a price on carbon.

1 . A process for obtaining methane from beneath a surface of the Earth comprising:
 collecting a native brine comprising methane at the surface from a first well;   extracting methane from the native brine, wherein the extraction is done by reducing pressure on the native brine.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The process of  claim 1 , wherein the temperature of the collected native brine is 100° F. or more. 
     
     
         5 . The process of  claim 1 , wherein the first well is in a non-geopressured-geothermal aquifer. 
     
     
         6 . The process of  claim 1 , wherein the first well is in a geopressured-geothermal aquifer. 
     
     
         7 - 9 . (canceled) 
     
     
         10 . The process of  claim 1 , further comprising extracting geothermal energy from the collected native brine comprising methane by heat exchange. 
     
     
         11 - 21 . (canceled) 
     
     
         22 . A process for obtaining methane from beneath a surface of the Earth comprising:
 collecting a native brine comprising methane at the surface from a first well;   extracting methane from the native brine, wherein the extraction is done by educing pressure on the native brine; and   burning the methane in a gas turbine or steam boiler to generate electricity or compressing the methane to form compressed natural gas (CNG), rocket fuel, liquefied natural gas, or combinations thereof.   
     
     
         23 . The process of  claim 22 , further comprising injecting the native brine after extracting the methane into a second well. 
     
     
         24 - 26 . (canceled)