A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.