Systems for generating energy from geothermal sources and methods of operating and constructing same

1 . A system for generating energy from geothermal sources, the system comprising:

a first injection well extending underground into a rock formation;

a first production well extending underground into the rock formation in proximity to the first injection well;

a first lateral section connected to and extending away from a location along the first injection well;

a second lateral section connected to and extending away from a location along the first production well; and

a first multilateral connector joining the first lateral section and the second lateral section;

each of the first injection well, the first production well, the first and second lateral sections being cased in steel and cemented in place within the rock formation;

the first injection well, the first lateral section, the first multilateral connector, the second lateral section and the first production well cooperating with each other to define a first pressure-tested downhole well loop within the rock formation and in a heat transfer arrangement therewith, the first pressure-tested downhole well loop being configured to receive a working fluid capable of undergoing phase change between liquid and gas within the first pressure-tested downhole well loop as a result of heat transferred from the rock formation;

a second injection well extending underground into the rock formation;

a second production well extending underground into the rock formation in proximity to the second injection well;

a third lateral section connected to and extending away from a location along the second injection well;

a fourth lateral section connected to and extending away from a location along the second production well;

a second multilateral connector joining the third and fourth lateral sections;

each of the second injection well, the second production well, the third and fourth lateral sections being cased in steel and cemented in place within the rock formation;

the second injection well, the third lateral section, the second multilateral connector, the fourth lateral section and the second production well cooperating with each other to define a second pressure-tested downhole well loop within the rock formation and in a heat transfer arrangement therewith, the second pressure-tested downhole well loop being configured to receive the working fluid capable of undergoing phase change between liquid and gas within the second pressure-tested downhole well loop as a result of heat transferred from the rock formation;

at least one pump fluidly connected to the first and second injection wells, the at least one pump being configured to circulate the working fluid through the first and second pressure-tested downhole well loops;

at least one turbine system configured to receive the working fluid from the first production well of the first pressure tested downhole well loop and the second production well of the second pressure-tested downhole well loop; the at least one turbine system being operable to convert mechanical energy generated from the flow of working fluid, into electricity; and

at least one cooler fluidly connected to the at least one pump and the at least one turbine for cooling the working fluid.

2 . The system of claim 1 further comprising an access well having a lateral segment within which is disposed the first multilateral connector.

3 . The system of claim 2 , wherein the second multilateral connector is positioned within the lateral segment of the access well at a location spaced apart from the first multilateral connector.

4 . The system of claim 1 , wherein the first injection well includes a first inlet, the first production well includes a first outlet, the second injection well includes a second inlet, and the second production well includes a second outlet, the second inlet and the second outlet being located on the surface in proximity to each other.

5 . The system of claim 4 , wherein the first inlet is disposed at a distance of between 7 m and 50 m from the first outlet.

6 . The system of claim 4 , wherein the second inlet is disposed at a distance of between 7 m and 50 m from the second outlet.

7 . The system of claim 4 , wherein the first inlet and the second inlet being located on the surface in proximity to each other, the first inlet being at least a distance of 20 m from the second inlet.

8 . The system of claim 4 , wherein the first outlet and the second outlet being located on the surface in proximity to each other, the first outlet being at least a distance of 20 m from the second outlet.

9 . The system of claim 1 further comprising:

a first injection well surface casing surrounding the first inlet and extending partially above the first injection well surface and configured to prevent the escape of the working fluid into the rock formation; and

a second injection well surface casing surrounding the second inlet and extending partially above the second injection well surface and configured to prevent the escape of the working fluid into the rock formation.

10 . The system of claim 1 further comprising:

a first production well surface casing surrounding the first outlet and extending partially above the first production well surface and configured to prevent the escape of the working fluid into the rock formation; and

a second production well surface casing surrounding the second outlet and extending partially above the second production well surface and configured to prevent the escape of the working fluid into the rock formation.

11 . The system of claim 1 wherein:

the at least one pump includes a first pump fluidly connected to the first injection well, the first pump being configured to circulate the working fluid through the first pressure-tested downhole well loop; and

the at least one pump includes a second pump fluidly connected to the second injection well, the second pump being configured to circulate the working fluid through the second pressure-tested downhole well loop.

12 . The system of claim 11 further comprising a splitter connecting piece configured to divert a stream of working fluid exiting the at least one turbine system toward the first and second pumps.

13 . The system of claim 1 wherein:

the first production well includes a first outlet and the second production well includes a second outlet; and

the system further comprising a merging connecting piece fluidly connecting the first and second outlets to the at least one turbine for merging the streams of working fluid flowing out of the first and second outlets.

14 . The system of claim 1 wherein the at least one turbine system includes a first turbine system fluidly connected to the first production well and the second turbine system fluidly connected to the second production well.

15 . The system of claim 1 , wherein the system has an above ground surface area of 45000 m 2 .

16 . The system of claim 1 wherein each of the first and second pressure-tested downhole loops are configured to withstand pressures of at least 7 MPa.

17 . The system of claim 16 wherein the hydrocarbon-based fluid is a hydrocarbon-based working fluid.

18 . The system of claim 1 wherein the working fluid is selected from the group consisting of a refrigerant, a hydrocarbon-based fluid, ammonia, carbon dioxide, and water.

19 . A system for generating energy from geothermal sources, the system comprising:

first and second pressure-tested downhole well loops formed within the rock formation and in a heat transfer arrangement therewith, each of the first and second pressure-tested downhole well loops being configured to receive a working fluid capable of undergoing phase change between liquid and gas within the first and second pressure-tested downhole well loops as a result of heat transferred from the rock formation; each of the first and second pressure-tested downhole well loops being defined by:

an injection well extending underground into a rock formation;

a production well extending underground into the rock formation in proximity to the injection well;

a first lateral section connected to and extending away from a location along the injection well;

a lateral section connected to and extending away from a location along the production well; and

a multilateral connector joining the first lateral section and the second lateral section;

each of the injection well, the production well, the first and second lateral sections being cased in steel and cemented in place within the rock formation;

at least one pump fluidly connected to the injection well of each of the first and second pressure-tested downhole well loops, the at least one pump being configured to circulate the working fluid through the first and second pressure-tested downhole well loops;

at least one turbine system configured to receive the working fluid from the production well of each of the first and second pressure-tested downhole well loops; the at least one turbine system being operable to convert mechanical energy generated from the flow of working fluid, into electricity; and

at least one cooler fluidly connected to the at least one pump and the at least one turbine for cooling the working fluid.

20 . A system for generating energy from geothermal sources, the system comprising:

a plurality of pressure-tested downhole well loops formed within the rock formation and in a heat transfer arrangement therewith, each plurality of pressure-tested downhole well loops being configured to receive a working fluid capable of undergoing phase change between liquid and gas within the plurality of pressure-tested downhole well loops as a result of heat transferred from the rock formation; each of the plurality of pressure-tested downhole well loops being defined by:

an injection well extending underground into a rock formation;

a production well extending underground into the rock formation in proximity to the injection well;

a first lateral section connected to and extending away from a location along the injection well;

a lateral section connected to and extending away from a location along the production well; and

a multilateral connector joining the first lateral section and the second lateral section;

each of the injection well, the production well, the first and second lateral sections being cased in steel and cemented in place within the rock formation;

at least one pump fluidly connected to the injection well of each of the plurality of pressure-tested downhole well loops, the at least one pump being configured to circulate the working fluid through the plurality of pressure-tested downhole well loops;

at least one turbine system configured to receive the working fluid from the production well of each of the plurality of pressure-tested downhole well loops; the at least one turbine system being operable to convert mechanical energy generated from the flow of working fluid, into electricity; and

at least one cooler fluidly connected to the at least one pump and the at least one turbine for cooling the working fluid.

21 . The system of claim 20 wherein the at least one pump includes a plurality of pumps corresponding to the plurality of pressure-tested downhole well loops.

22 . The system of claim 20 wherein the at least one turbine system includes a plurality of turbine systems corresponding to the plurality of pressure-tested downhole well loops.

23 . The system of claim 20 wherein the at least one cooler includes a plurality of coolers corresponding to the plurality of pressure-tested downhole well loops.

24 . The system of claim 21 further comprising a controller operable to selectively switch off one or more of the plurality of pumps.