| CPC F24T 10/20 (2018.05) [E21B 36/00 (2013.01); E21B 43/267 (2013.01)] | 7 Claims |
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1. A method of producing work from a geothermal resource, comprising:
locating a rock formation suited for development as a geothermal resource;
drilling a wellbore which allows the rock formation to be accessible via a plunging fracture generated from the wellbore, wherein the plunging fracture is sited in a zone with tectonic stress;
generating the plunging fracture from the wellbore at a depth of 15,000 feet in a sedimentary stratum with a porosity less than 5% by
injecting a mixture of finely ground calcium carbonate based “white mud” loaded with 10 volume % rubber particles ranging in size from 0.05 mm to 2.5 mm, wherein the mixture comprises a density between 10 PPG and 14 PPG, and further wherein the mixture generates a fracture to a depth of 25,000 feet,
expanding the plunging fracture until thermal effects increase the Poisson ratio of the rock formation, and
terminating downward growth of the plunging fracture by increasing fracture gradient and fracture toughness,
wherein the plunging fracture provides access to the rock formation via the wellbore; and
producing work from the rock formation in an open loop configuration,
wherein the producing comprises circulating a fluid into the fracture at a depth 100 meters below the top of the fracture via the wellbore to convert the fluid to a heated fluid, recovering the heated fluid from the fracture at the top of the fracture via the wellbore, producing work from the heated fluid, and returning the heated fluid to the fracture via the wellbore.
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