Carbon dioxide-based geothermal energy generation systems and methods related thereto

Abstract

A system comprises an injection well in communication with an underground reservoir that is at a first temperature and that contains a native fluid, a production well in communication with the reservoir, and a supply system providing a non-water based working fluid to the injection well at a second temperature lower than the first temperature. Exposure of the working fluid to the first temperatures heats the working fluid to a third temperature that is higher than the second temperature. At least a portion of the working fluid at the third temperature enters the production well and is produced from the reservoir as a production fluid. An energy recovery apparatus in fluid communication with the production well converts energy contained in the production fluid to electricity, heat, or a combinations thereof.

1 . A system comprising:
 one or more injection wells for accessing one or more underground reservoirs, the one or more reservoirs being at one or more first temperatures and containing at least one native fluid, each of the one or more injection wells having an injection well reservoir opening in fluid communication with one of the one or more reservoirs;   one or more production wells each having a production well reservoir opening in fluid communication with one of the one or more reservoirs;   a working-fluid supply system for providing a non-water based working fluid to the one or more injection wells at a second temperature lower than the one or more first temperatures,   wherein the working-fluid supply system, the one or more injection wells, and the one or more production wells are configured to store at least a first portion of the non-water based working fluid in the one or more reservoirs for a specified period of time,   wherein exposure of the working fluid to the one or more first temperatures heats the working fluid to a third temperature that is higher than the second temperature, wherein at least a second portion of the working fluid that is at the third temperature enters the one or more production well reservoir openings and is produced from the one or more reservoirs via the one or more production well to provide a production fluid; and   an energy recovery apparatus in fluid communication with the one or more productions wells, wherein energy contained in the production fluid is converted to electricity, heat, or a combination thereof, in the energy recovery apparatus.   
     
     
         2 . The system of  claim 1 , wherein the at least one native fluid includes a solution comprising methane,
 wherein exposure of the non-water based working fluid to the at least one native fluid causes methane to come out of the solution with the native fluid such that the production fluid comprises methane that had come out of the solution, and   wherein the energy recovery apparatus comprises at least one separation apparatus that separates at least a portion of the methane from the production fluid.   
     
     
         3 . The system of  claim 2 , wherein the energy recovery apparatus further comprises a heater that combusts at least a portion of the separated methane and heats the production fluid to a fourth temperature that is higher than the third temperature to provide a heated production fluid. 
     
     
         4 . The system of  claim 1 , wherein the energy recovery apparatus further comprises at least one of: one or more electricity-generating devices; one or more heat exchangers; or a combination thereof to convert energy contained in the production fluid to electricity, heat energy, or a combination thereof. 
     
     
         5 . The system of  claim 1 , wherein the energy recovery apparatus comprises at least one heat recovery apparatus for recovering heat from at least a first portion of the production fluid to heat a second portion of the production fluid. 
     
     
         6 . The system of  claim 1 , wherein the at least one native fluid further comprises at least one hydrocarbon, wherein the production fluid comprises at least a portion of the at least one hydrocarbon, and wherein the energy recovery apparatus further comprises:
 one or more separation units to separate the at least one hydrocarbon from the production fluid; and   a heat recovery apparatus configured to recover heat energy from at least one of the one or more separation units, the separated at least one hydrocarbon, or the separated production fluid.   
     
     
         7 . The system of  claim 1 , wherein the one or more reservoirs comprise a brine aquifer and the at least one native fluid comprises a brine with methane dissolved in the brine. 
     
     
         8 . The system of  claim 1 , wherein the reservoir comprises a partially-depleted oil or natural gas field and the at least one native fluid comprises at least one hydrocarbon. 
     
     
         9 . The system of  claim 1 , wherein the non-water based working fluid is carbon dioxide. 
     
     
         10 . The system of  claim 1 , wherein the specified period of time is a temporary period of time, a semi-permanent period of time, a substantially permanent period of time, or a permanent period of time. 
     
     
         11 . The system of  claim 1 , wherein the production fluid comprises from 0.01 wt % to 99 wt % of the non-water based working fluid. 
     
     
         12 . A system comprising:
 one or more injection wells for accessing one or more underground reservoirs, the one or more reservoirs being at one or more first temperatures, each of the one or more injection wells having an injection well reservoir opening in fluid communication with at least one of the one or more reservoirs;   one or more production wells each having a production well reservoir opening in fluid communication with at least one of the one or more reservoirs;   a working-fluid supply system for providing a non-water based working fluid to the one or more injection wells at a second temperature,   wherein exposure of the non-water based working fluid to the one or more first temperatures results in heat energy being exchanged between the non-water based working fluid and the one or more reservoirs to provide a production fluid at a third temperature, wherein at least a portion of the production fluid at the third temperature enters the production well reservoir opening and is produced from the reservoir via the one or more production wells to provide a produced fluid; and   an energy recovery apparatus in fluid communication with the one or more production wells, the energy recovery apparatus including equipment that generates waste heat and at least one heat recovery apparatus configured to recover at least a portion of the waste heat from the equipment and uses the recovered portion of the waste heat to heat the produced fluid to a fourth temperature that is higher than the third temperature to provide a heated produced fluid.   
     
     
         13 . The system of  claim 12 , wherein the equipment that generates waste heat comprise at least one of: a compressor for compressing at least a portion of the produced fluid or the working fluid; a pump for moving at least a portion of the produced fluid or the working fluid; an expansion device or generator for electricity generation; an enhanced oil recovery system; a co-located facility. 
     
     
         14 . The system of  claim 13 , wherein the co-located facility comprises a fuel production facility or a power plant. 
     
     
         15 . The system of  claim 14 , wherein the fuel production facility comprises an ethanol production facility or a biofuel production facility. 
     
     
         16 . The system of  claim 12 , wherein the energy recovery apparatus further comprises at least one of: one or more electricity-generating devices; one or more heat exchangers; or a combination thereof to convert energy contained in the heated produced fluid to electricity, heat energy, or a combination thereof. 
     
     
         17 . The system of  claim 12 , wherein the reservoir comprises a brine aquifer. 
     
     
         18 . The system of  claim 12 , wherein the reservoir comprises a partially-depleted oil or natural gas field and the native fluid comprises at least one hydrocarbon. 
     
     
         19 . The system of  claim 12 , wherein the non-water based working fluid is carbon dioxide. 
     
     
         20 . The system of  claim 12 , wherein the production fluid comprises from 0.01 wt % to 99 wt % of the non-water based working fluid.