In Situ thermal processing of a hydrocarbon containing formation to produce sulfur containing formation fluids

A method of treating a hydrocarbon containing formation in situ, comprising:

• providing heat from one or more heaters disposed in the formation to at least a portion of the formation;
• allowing the heat to transfer directly from the one or more heaters to a part of the formation thereby pyrolyzing at least some hydrocarbons within the part of the formation;
• and
• producing a mixture from the formation, wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1% by weight, when calculated on an atomic basis, of the condensable hydrocarbons is sulfur.