Patent ID: 7980312
Filing Date: 2011-07-19
Classification: E21B

Abstract:
1. A method of producing hydrocarbons in situ from an oil shale fixed-bed hydrocarbon disposed below a ground surface and having a substantially horizontal, naturally occurring, water-flow leached, higher permeability zone next to and substantially parallel to a lower permeability zone, the steps comprising: producing at least one injection opening in the naturally occurring, water-flow leached higher permeability zone of the formation, the injection opening having a first vertical depth; providing at least one production opening in the higher permeability zone of the formation, the production opening having a second vertical depth, the first vertical depth of the injection opening approximately the same depth as the second vertical depth of the production opening, the same depth of the injection opening and the production opening providing horizontal communication there between; injecting a heated thermal-energy carrier fluid into the injection opening; circulating the carrier fluid horizontally through the higher permeability zone and parallel thereto; pyrolyzing the hydrocarbons in the lower and higher permeability zone in situ by heating the higher permeability zone and the adjacent lower permeability zone along an interface of the higher permeability zone and adjacent lower permeability zone extending substantially between from the injection opening to the production opening; producing at least a portion of the mobilized hydrocarbons by flowing the carrier fluid with the pyrolyzed hydrocarbons through the production opening to the ground surface; and removing at least one selected hydrocarbon held in the carrier fluid.