Combined development of oil shale by in situ heating with a deeper hydrocarbon resource

A method for producing hydrocarbons from subsurface formations at different depths is first provided. In one aspect, the method includes the step of heating organic-rich rock, in situ, within a subsurface formation at a first depth. The result of the heating step is that at least a portion of the organic-rich rock is pyrolyzed into hydrocarbon fluids. Preferably, the organic-rich rock of the subsurface formation of the first depth is oil shale. The method also includes providing at least one substantially unheated zone within the formation of the first depth. In this way, the organic-rich rock in that zone is left substantially unpyrolyzed. The method further includes drilling at least one production well through the unheated zone, and completing the at least one production well in a subsurface formation at a second depth that is deeper than the first depth. Thereafter, hydrocarbon fluids are produced through the at least one production well.