The invention relates to methods for extracting a kerogen-based product from subsurface shale formations. The methods utilize in-situ reactions of kerogen involving liquid phase chemistry at formation temperatures and pressures. These methods rely on chemically modifying the shale-bound kerogen to render it mobile, using chemical oxidants. In one embodiment, an oxidant is provided to the subsurface shale formation comprising kerogen in an inorganic matrix, the oxidant converting the kerogen to form organic acids, and forming a mobile kerogen-based product. The spent oxidant is regenerated in-situ to restore at least some of the original oxidation activity. At least a portion of the mobile kerogen-based product is recovered. The kerogen-derived product can be upgraded to provide commercial products.