NOVELTY - Heat from heat source(s) (6700, 6702) is provided to portion(s) of relatively permeable formation containing heavy hydrocarbons in situ, transferred to selected section of formation. Heat from heat source(s) is controlled such that an average temperature within the selected section of the formation is less than 375 degrees C and a mixture is produced.    USE - For producing condensable and non-condensable hydrocarbons such as pyridines, thiophenes, anthracenes, pyrroles, methane, olefins, molecular hydrogen, ammonia, for recovering thermal energy (all claimed), methanol, gasoline, diesel fuel and middle distillates.    ADVANTAGE - The treatment of relatively permeable formation containing HC in situ provides mixture of relatively high quality HC product, hydrogen and/or other products. By heating a portion of the relatively permeable formation, electrical energy cost associated with heating is reduced, thereby a more economical process is provided for heating. The recovery efficiency of synthesis gas (SG) is improved. The presence of methane increases the heating value of the produced SG.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for e.g.:    (1) a method of treating layer of relatively permeable formation containing heavy hydrocarbons (HC);    (2) an in situ method for producing hydrogen from relatively permeable formation;    (3) a method for forming and installing heater wells in relatively permeable formation which involves forming wellbore (I) in formation, forming wellbore (II) in formation using magnetic tracking such that wellbore is arranged parallel to wellbore (I) and providing heat source(s) within wellbores (I, II) such that heat is provided to at least a portion of formation;    (4) a system configured to heat formation, which comprises heater heats disposed in opening of formation to heat formation, oxidizing fluid source, conduit disposed in opening. The conduit is configured to provide oxidizing fluid from source to reaction zone in formation. The oxidizing fluid is chosen from hydrocarbons. The system is configured to allow heat to transfer substantially by conduction from reaction zone to a pyrolysis zone of formation during use;    (5) an in situ method for heating formation which involves heating a portion of formation to a temperature to support reaction of hydrocarbons within portion of formation with an oxidizing fluid. The oxidizing fluid is provided to reaction zone and allowed to react with at least a portion of HC at reaction zone to generate heat; and    (6) a method for producing synthesis gas from formation which involves heating a section of formation to generate synthesis gas, providing a synthesis gas generating fluid to section and removing synthesis gas from formation.    DESCRIPTION OF DRAWING(S) - The figure shows the endview schematic of a method for treating a relatively permeable formation using the combination of producer and heater wells in the formation.    Heat sources (6700,6702)