TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: Controlling formation conditions comprises maintaining a temperature within the selected section within pyrolysis range. Formation conditions are controlled with a valve coupled to the heat source(s). The pressure and temperature is controlled within a majority of the selected section of the formation, in which the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure. The heat is controlled such that an average heating rate of the selected section is less than 1degreesC/day during pyrolysis. Providing heat from the heat source(s) comprises heating a selected volume (V) of the hydrocarbon containing formation, in which the formation has an average heat capacity (Cv) and in which the heating pyrolyzes some hydrocarbons within the selected volume. The heat is allowed to transfer from the heat source(s) by conduction. Heat is provided from the heat source(s) by heating the selected section such that a thermal conductivity of the portion of the selected section is greater than 0.5 W./(mdegreesC). Altering a pressure within the formation inhibits production of hydrocarbons from the formation having carbon numbers greater than 25. Hydrogen (H2) is provided to the heated section to hydrogenate hydrocarbons. A portion of the section is heated with heat from hydrogenation. Allowing the heat to transfer comprises increasing a permeability of a majority of the selected section to greater than 100 millidarcy. The heat is controlled to yield greater than 60 wt.% of condensable hydrocarbons. The produced mixture is separated into gas and liquid streams (811, 813), in which the liquid stream is separated into aqueous and non-aqueous streams. The mixture is produced from a production well (825), in which heating is controlled such that the mixture can be produced from the formation as vapor. Preferred Parameter: Heating energy/day provided to the volume is at mostPwr in which Pwr = hasteriskVasteriskCvrhoB (where h = is an average heating rate of the formation, rho = is formation bulk density, in which the heating rate is less than 10degreesC/day). The controlling pressure is 2 bar absolute. The produced mixture comprises a partial pressure of H2 within the mixture greater then 0.5 bar. The minimum pyrolysis temperature is 270degreesC. The pressure within the formation is controlled at atmospheric pressure to 100 bar. The minimum pyrolysis temperature is 270degreesC. Preferred Property: The produced mixture comprises condensable hydrocarbons having an American Petroleum Institute (API) gravity of at least25degrees. The API gravity of the produced mixture is controlled to be greater than 25degrees API by controlling average pressure and temperature in the selected section. The average pressure in the selected section is greater than the pressure (p) set forth in the following equation for an assessed average temperature (T) in the selected section: p = e(-44000/T+67), preferably p = (-22000/T+51) (p is measured in psi and T is measured in degreesK).    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Component: The heat source(s) can be electrical heaters (803), surface burners, flameless distributed combustors, or natural distributed combustors. The conduit comprises critical flow orifices. A conductor is disposed in a second conduit which is disposed within the opening. A heat exchanger is disposed external to the formation.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The produced mixture comprises condensable hydrocarbons, non-condensable hydrocarbons, in which a molar ratio of ethene to ethane is 0.001-0.15. The condensable hydrocarbons contains olefin (0.1-15 wt.%), phenols (5-30 wt.%), aromatic compounds (greater than 20 wt.%), multi-ring aromatics (less than 5 wt.%) having more than 2 rings, asphaltenes (less than 0.3 wt.%), cycloalkanes (5-30 wt.%).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The condensable hydrocarbon also contains nitrogen (less than 0.1 wt.%), oxygen (less than 1 wt.%), and sulfur (less than 1 wt.%). The produced mixture can be ammonia (0.05 wt.%) which is used to produce fertilizer. The non-condensable component comprises H2 (greater than 10 but less than 80 wt.%). The produced mixture comprises hydrogen sulfide (H2S), and carbon dioxide (CO2).