Hydrologic cells for recovery of hydrocarbons or thermal energy from coal, oil-shale, tar-sands and oil-bearing formations

An underground system for recovery of hydrocarbons and thermal energy in the form of hot gases from host-rock formations bearing coal, oil shale, tar-sands or oil which system comprises a hydrologic cell located within said formations, said hydrologic cell having at least one source-aquifer and one sink-aquifer, and host-rock located between said source-aquifer and said sink-aquifer, said source-aquifer and said sink-aquifer each being independently connected to the ground surface by a series of boreholes drilled in said host-rock, said boreholes connecting said source-aquifer with the surface being capable of conveying extracting fluid, fuel and oxygen to said source-aquifer, said boreholes connecting said sink-aquifer with the surface being capable of moving extracted thermal energy from said sink-aquifer to the surface, means for igniting said fuel and oxygen located in said source-aquifer, means for moving said extracting fluid, fuel and oxygen from said source-aquifer through said host-rock to said sink-aquifer and means for removing said extracted thermal energy from said sink-aquifer through said boreholes to said ground surface.