NOVELTY - Heaters located in the tar sand formation have horizontal heating sections in the hydrocarbon layer (460) of the formation. The heaters provide heat to the hydrocarbons in the formation. The heat creates converging drainage paths for mobilized fluids. A production well collects and produces mobilized fluids from the converged drainage paths in the hydrocarbon layer. Heating the tar sand formation increases permeability and porosity of the formation caused by a reduction of mass in the formation due to vaporization and removal of water, removal of hydrocarbons and creation of fractures.    USE - For the production of hydrocarbons, hydrogen, and other products from tar sand formations. Produced hydrocarbons are utilized to form transportation fuel such as JP-8 jet fuel, gasoline or pipeline gas.    ADVANTAGE - The process economically produces crude products, hydrocarbons, hydrogen, and other products from hydrocarbon-containing formations. The heat source in production well allows for vapor phase removal of formation fluids from the formation. Providing heating at or through the production well may inhibit condensation and/or refluxing of production fluid when such production fluid is moving in the production well proximate the overburden. Heating increases heat input into the formation and increases production rate from the production well as compared to a production well without a heat source. It also inhibits condensation of high carbon number compounds (C6 and above) in the production well, and increases formation permeability at or proximate the production well. Pressure in the formation may be maintained high enough to promote production of formation fluid with an API gravity of greater than 20degrees. Maintaining high pressure in the formation also inhibits formation subsidence during in situ heat treatment. It also facilitates vapor phase production of fluids from the formation which allows for a reduction in size of collection conduits used to transport fluids produced from the formation. Maintaining increased pressure also reduces or eliminates the need to compress formation fluids at the surface to transport the fluids in collection conduits to treatment facilities. Large quantities of hydrocarbons of increased quality and of relatively low molecular weight are produced. The formation fluid produced has a minimal amount of compounds above a selected carbon number at most 25, 20, 12, or 8. Entrainment of high carbon number compounds and multi-ring hydrocarbon compounds in the vapor is also inhibited. These compounds may remain in a liquid phase in the formation for significant time periods sufficient enough for the compounds to pyrolyze and form lower carbon number compounds.    DETAILED DESCRIPTION - The heaters superimpose over the production well to create a path for the mobilized fluids to flow to the production well.    An INDEPENDENT CLAIM is included for treating a tar sand formation.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional representation of a removable conductor-in-conduit heat source.    Hydrocarbon layer (460)    Casings (530)    Legs (624,626,628)    Transformer (634)    Lead-in conductors (636)