NOVELTY - A hydrocarbon containing formation is treated in situ by heating portion(s) of the formation to allow pyrolysis of the hydrocarbons; controlling the heat so that an average temperature within most of the selected section/volume of the formation is less than 375degreesC; and producing a mixture of high quality hydrocarbon products, hydrogen and other products from the formation.    USE - The method is used to produce a gas mixture containing ammonia, which is useful in the production of fertilizer (claimed). The synthesis gases produced may be converted to heavier condensable hydrocarbons, e.g. a Fischer Tropsch hydrocarbon synthesis process, which may be configured to convert synthesis gas to, branched and unbranched paraffins. The produced synthesis gas may be (a) used in a catalytic methanation process to produce methane; (b) used for producing methanol, gasoline and diesel fuel, ammonia, and middle distillates; (c) combusted as fuel; (d) used for synthesizing a wide range or organic and/or inorganic compounds, i.e. hydrocarbons and ammonia; (e) used to generate electricity by combusting it as fuel, by reducing the pressure of the synthesis gas in turbines, and/or using temperature of the synthesis gas to make steam and then run turbines; and (f) used in an energy generation unit, i.e. as molten carbonate fuel cell, a solid oxide fuel cell, or other type of fuel cell. The hydrogen produced may be used to upgrade oil. The paraffins may be used to produce other products, i.e. diesel, jet fuel and naphtha products.    ADVANTAGE - The inventive method converts the hydrocarbons within a hydrocarbon containing formation in situ within the formation to yield a mixture of relatively high quality hydrocarbon products, hydrogen and other products. It allows removal of the hydrocarbons, hydrogen and other formation fluids from the formation through production wells. The temperature and pressure in portion(s) of the formation may be controlled during pyrolysis to yield improved products from the formation.    DETAILED DESCRIPTION - A hydrocarbon containing formation is treated in situ by    (i) providing heat from heat source(s) (801) to portion(s) of the formation;    (ii) allowing the heat to transfer from the heat source(s) to a selected section of the formation;    (iii) controlling the heat from the heat source(s) so that an average temperature within most of the selected section of the formation exceeds 270degreesC but is less than 375degreesC to pyrolyze the hydrocarbons within the heated portion of the formation; and    (iv) producing a mixture from the formation comprising an olefin content (less than 10 wt.%) and an average carbon number less than 35; non-condensable hydrocarbons comprising hydrocarbons having carbon numbers of less than 5 where a weight ratio of hydrocarbons having 2-4 carbon numbers to methane is greater than 1; ammonia where greater than 0.5 wt.% of the mixture comprises ammonia; and condensable hydrocarbons comprising oxygenated hydrocarbons where greater than 5 wt.% of the condensable component comprises oxygenated hydrocarbons.    INDEPENDENT CLAIMS are included for the following:    (a) method of forming heater wells in a hydrocarbon containing formation comprising forming a first wellbore in the formation, forming a second wellbore in the formation using magnetic tracking so that the second wellbore is arranged parallel to the first wellbore, and providing heating mechanism(s) within the first wellbore and heating mechanism(s) within the second wellbore so that the heating mechanisms can provide heat to portion(s) of the formation;    (b) system, configured to heat a hydrocarbon containing formation and allow heat to transfer by conduction from the reaction zone to a pyrolysis zone of the formation during use, comprising a heater in an opening in the formation, an oxidizing fluid source, a conduit in the opening;    (c) method of forming spent portion of formation within a hydrocarbon containing formation;    (d) method for sequestering carbon dioxide within a hydrocarbon containing formation; and    (e) method for producing ammonia using a carbon containing formation.    DESCRIPTION OF DRAWING(S) - The figure shows the method using pyrolysis water to generate synthesis gas in a formation.    Heat source (801)    Electrical heaters (803)    Liquid stream (811)    Gas stream (813)