NOVELTY - Treating a hydrocarbon containing formation in situ comprises: (1) providing heat from at least one heat source to at least portion of the formation; (2) transferring heat from the heat source(s) (801) to a selected section of the formation and (3) controlling heat from the source(s) so that an average temperature in at least a majority of the section is less than 375degreesC and (4) producing a mixture from the formation.    USE - Used for in situ treatment of a hydrocarbon containing formation (e.g. a subsurface formation which is a spent portion of the formation, an oil reservoir, or a hydrocarbon formation located over 760 m below ground surface).    ADVANTAGE - The method economically produces hydrocarbons, hydrogen, and/or other products from hydrocarbon containing formations. It increases transfer of vapors through the treated portion of the formation through an increased permeability due. It reduces the number of production wells required to produce a mixture from the formation. It increases economic viability by reducing the number of production wells required for the production.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (A) forming heater wells in the hydrocarbon containing formation, which comprises forming a first wellbore in the formation; forming a second wellbore in the formation using a magnetic tracking, so that the second wellbore is parallel to the first wellbore and providing at least one heating mechanism within the respective first and second wellbores, so that the heating mechanisms can provide heat to at least a portion of the formation;    (B) a system configured to heat the hydrocarbon containing formation, which comprises a heater in an opening in the formation and configured to provide heat to at least a portion of the formation during use; an oxidizing fluid source and a conduit in the opening and configured to provide an oxidizing fluid from the oxidizing fluid source to a reaction zone in the formation during use;    (C) in situ production of synthesis gas from the hydrocarbon containing formation, which comprises heating a section of the formation to a temperature to allow synthesis gas (823) generation, where a permeability of the section is uniform and greater than the permeability of an unheated section of the formation when the temperature to allow synthesis gas generation within the formation is achieved; providing a synthesis gas generating fluid (818, 821) to the section to generate synthesis gas and removing the synthesis gas from the formation;    (D) forming a spent portion of the formation within the hydrocarbon containing formation, which comprises heating a first portion (805) of the formation to pyrolyze hydrocarbons within the first portion and to establish a uniform permeability within the first portion and cooling the first portion;    (E) sequestering carbon dioxide (CO2) within the hydrocarbon containing formation, which comprises heating a portion of the formation to increase permeability and form the uniform permeability within the portion; allowing the portion to cool and storing CO2 within the portion;    (F) in situ production of energy from the hydrocarbon containing formation, which comprises providing heat from the heat source(s) to at least a portion of the formation; allowing the heat to transfer from the heat source(s) to the section of the formation, so that the heat from the heat source(s) pyrolyzes at least a portion of the hydrocarbons within the section; providing pyrolysis products from the formation; providing at least a portion of the pyrolysis products to a reformer to generate synthesis gas; producing the synthesis gas from the reformer; providing at least a portion of the produced synthesis gas to a fuel cell to produce electricity, where the fuel cell produces a CO2 containing exit stream; and storing at least a portion of the CO2 in the CO2 containing exit stream in a subsurface formation; and    (G) producing ammonia using a carbon containing formation, which comprises separating air to produce oxygen (O2) and nitrogen (N2) rich streams; heating the section of the formation to a temperature to support reaction of carbon-containing material in the formation to form the synthesis gas; providing the synthesis gas generating fluid and at least a portion of the O2 rich stream to the selected section; allowing the synthesis gas generating fluid and O2 in the O2 rich stream to react with at least a portion of the carbon-containing material in the formation to generate synthesis gas; producing synthesis gas from the formation, where the synthesis gas comprises hydrogen (H2) and carbon monoxide (CO); providing at least a portion of the H2 in the synthesis gas to an ammonia synthesis process; providing N2 to the ammonia synthesis process and using the ammonia synthesis process to generate ammonia. The oxidizing fluid is selected to oxidize at least some hydrocarbons at the reaction zone during use such that heat is generated at the reaction zone. The system is configured to allow heat to transfer by conduction from the reaction zone to a pyrolysis zone of the formation during use.    DESCRIPTION OF DRAWING(S) - The figure shows a diagram of using pyrolysis water to generate synthesis gas in a formation.    Heat sources (801)    Electrical heaters (803)    First portion (805)    Pyrolyzation fluid (807)    Synthesis gas generating fluid (818, 821)    Synthesis gas (823)    Production well (825)