NOVELTY - A method of treating a hydrocarbon bearing formation comprises heating with one or more heaters to raise the temperature of the selected formation to less than about 375 degrees C and recovering a mixture from the formation.    USE - For producing synthesis gas, carbon material which is used for steel manufacture, and ammonia which is used for producing urea (claimed). The synthesis gas is used for producing paraffins which are used for diesel, jet fuel and naphtha product, and for producing methane, methanol, gasoline, diesel fuel and ammonia. The synthesis gas is used as combustion fuel for heating the formation. The synthesis gas is used in energy generation units such as molten carbonate fuel cell, solid oxide fuel cell and other type of fuel cell.    ADVANTAGE - A mixture of high quality hydrocarbon products, hydrogen and other product, is provided. The hydrocarbons are pyrolyzed within a larger area of portion, as spacing between the heat sources is selected to increase the effectiveness of the heat source, thereby the economic viability of selected in situ conversion process for hydrocarbon is increased. The superposition of the heat tends to increase the uniformity of heat distribution in selected section of the formation. The formation is heated by a more economical process, using systems having durability. The pressure of hydrogen in produced fluid is controlled, such that large amount of fluids having improved quality is provided. The porosity of the portion(s) of the formation is increased uniformly. The pyrolyzed portion(s) of formation has improved uniform permeability, thereby produces synthesis gas with high recovery efficiency.    DETAILED DESCRIPTION - A method of treating a hydrocarbon bearing formation comprises heating with one or more heaters to raise the temperature of the selected formation to less than about 375 degrees C and recovering a mixture from the formation. The hydrocarbons may be part pyrolyzed during heating. The thermal conductivity of the formation is at least 0.5 W/(m degrees C) and heat energy per day supplied is calculated from the formula pwr = hxVxrhoB where pwr = heating energy per day, h = average heating rate, and rhoB is the bulk formation density.    INDEPENDENT CLAIMS are included for the following:    (1) method of treating layer of hydrocarbon bearing formation in situ;    (2) an in situ method of heating the hydrocarbon bearing formation;    (3) an in situ method for producing hydrogen from hydrocarbon bearing formation;    (4) method for forming heater wells in hydrocarbon bearing formation;    (5) installation of heater well or wells in hydrocarbon bearing formation;    (6) system configured to heat formation of hydrocarbon;    (7) system configurable to heat formation of hydrocarbon;    (8) mixture produced from portion of hydrocarbon formation;    (9) condensable mixture produced from hydrocarbon formation;    (10) method for in situ production of synthesis gas from hydrocarbon formation;    (11) method of in situ synthesis gas production;    (12) method for in situ production of synthesis gas from formation containing carbon;    (13) method of forming spent portion of formation within hydrocarbon formation;    (14) method of sequestering carbon dioxide within hydrocarbon formation;    (15) in situ sequestration of carbon dioxide within hydrocarbon formation in situ;    (16) in situ production of energy from hydrocarbon formation;    (17) method for producing ammonia using formation containing carbon;    (18) method of treating permeable formation of hydrocarbon in situ; and    (19) method of treating hydrocarbon in at least a portion of hydrocarbon formation.