System and method for utilizing oil and gas wells for geothermal power generation

Abstract

A method and system for extracting geothermal heat from a well is provided, wherein the well casing has positioned therein an inner pipe nested within an outer pipe. The space between the well casing and the outer pipe may be filled with an insulating medium. A liquid heat conducting material flows into and down through the inner pipe. The inner pipe may be fitted with a one-way valve so that the liquid heat conducting material does not reverse direction and flow upwards towards the surface. As the liquid heat conducting material approaches the bottom of the inner pipe, it enters into a heat exchanger, absorbs heat and transforms to its gaseous state. The gas rises upward through the space between the outer pipe and the inner pipe and into the electricity generating component.

1 . A system for extracting geothermal heat from within a bore hole, comprising:
 well casing extending downward from the surface of the earth;   an outer pipe positioned concentrically within the well casing and extending downward into the well casing, wherein the lower end of the outer pipe is configured with an end to prevent the passage of water therefrom;   an inner pipe positioned concentrically within the outer pipe and extending downward into the outer pipe, wherein the lower end of the inner pipe is proximal to the lower end of the outer pipe;   a fluid delivery system for delivering fluid into the upper end of the inner pipe;   a gas recovery system for recovering gas from the upper end of the outer pipe and converting the gas to work.   
     
     
         2 . The heat extraction system of  claim 1 , wherein the fluid passes downward through the inner pipe and exits the bottom of the inner pipe and is prevented from entering the well casing due to the end of the outer pipe, geothermal heat sufficiently heats the water to cause a phase change from liquid to gas, and the gas rises through the space between the outside of the inner pipe and the inside of the outer pipe. 
     
     
         3 . The heat extraction system of  claim 1 , wherein at least a portion of the outer pipe and the inner pipe extend horizontally under the surface of the earth. 
     
     
         4 . The heat extraction system of  claim 1 , wherein the well casing include cracks or crevices in the rock resulting from the drilling of the well casing. 
     
     
         5 . The heat extraction system of  claim 1 , further including insulation placed between the outside of the outer tube and the inside of the well casing. 
     
     
         6 . The heat extraction system of  claim 1 , further including insulation placed between the outside of the outer tube and the inside of the well casing, wherein the insulation is configured to retain heat within the outer pipe in areas proximal to the surface of the earth and facilitate the flow of heat towards the outer pipe in areas proximal to the lowest end of the outer pipe. 
     
     
         7 . The heat extraction system of  claim 1 , further including a one-way valve inside the inner pipe, thereby preventing the fluid from reversing flow towards the surface of the earth. 
     
     
         8 . The heat extraction system of  claim 1 , wherein the conversion of gas to work includes the generation of electricity. 
     
     
         9 . A method for extracting geothermal heat from within a well casing, comprising:
 extending a well casing downward from the surface of the earth;   extending an outer pipe downward into the well casing, wherein the outer pipe is arranged concentrically within the well casing and wherein the lower end of the outer pipe is configured with an end to prevent the passage of water therefrom;   extending an inner pipe downward into the outer pipe, wherein the inner pipe is configured concentrically within the outer pipe and wherein the lower end of the inner pipe is proximal to the lower end of the outer pipe;   delivering a fluid into the upper end of the inner pipe;   recovering gas from the upper end of the outer pipe and converting the gas to work.   
     
     
         10 . The method of  claim 9 , wherein the fluid passes downward through the inner pipe and exits the bottom of the inner pipe and is prevented from entering the well casing due to the end of the outer pipe, geothermal heat sufficiently heats the water to cause a phase change from liquid to gas, and the gas rises through the space between the outside of the inner pipe and the inside of the outer pipe. 
     
     
         11 . The method of  claim 9 , wherein at least a portion of the outer pipe and the inner pipe extend horizontally under the surface of the earth. 
     
     
         12 . The method of  claim 9 , wherein a bore hole around the well casing includes cracks or crevices in the rock resulting from the insertion of the well casing in the bore hole. 
     
     
         13 . The method of  claim 9 , further including insulation placed between the outside of the outer tube and the inside of the well casing. 
     
     
         14 . The method of  claim 9 , further including insulation placed between the outside of the outer tube and the inside of the well casing, wherein the insulation is configured to retain heat within the outer pipe in areas proximal to the surface of the earth and facilitate the flow of heat towards the outer pipe in areas proximal to the lowest end of the outer pipe. 
     
     
         15 . The method of  claim 9 , further including a one-way valve inside the inner pipe, thereby preventing the fluid from reversing flow towards the surface of the earth. 
     
     
         16 . The method of  claim 9 , wherein the conversion of gas to work includes the generation of electricity.