Disclosed herein are methods for extracting a kerogen-based product from subsurface (oil) shale formations. These methods rely on chemically modifying the shale-bound kerogen using a chemical oxidant so as to render it mobile. The oxidant is provided to a formation fluid in contact with the kerogen in the subsurface shale. A mobile kerogen-based product which includes the organic acids is withdrawn from the subsurface shale formation and processed to isolate the organic acids contained therein. The isolated organic acids are upgraded by a reaction process that make the products suitable as refinery feedstocks, fuel or lubricant blendstocks, reaction intermediates, chemical feedstocks, or chemical intermediate blendstocks.