Conduction convection reflux retorting process

A sub-surface oil shale production system, comprising:

• a production well extending vertically from the surface to a location proximate the oil shale;
• an energy delivery well extending from the surface along a path including an arcuate portion, wherein said arcuate portion intersects said production well at a location proximate a bottom of the oil shale;
• a heater disposed in said energy delivery well operative to heat the oil shale;
• and
• a convection passage extending between said energy delivery well and said production well thereby forming a convection loop, said convection passage extending upwardly from the intersection of said arcuate portion and said production well.

A process for retorting and extracting sub-surface hydrocarbons, comprising:

• drilling an energy delivery well extending from the surface to a location proximate a bottom of the hydrocarbons;
• drilling a production well extending from the surface to a location proximate the hydrocarbon;
• forming a convection passage that extends between said energy delivery well and said production well thereby forming a convection loop;
• heating the hydrocarbons to form an oil pool and oil vapors;
• maintaining the pressure of the convection loop at a level that is sufficient to condense said oil vapors into oil condensate;
• and
• recycling said oil vapors and said oil condensate in said convection loop.