A system configured to heat a portion of a formation includes a plurality of heat sources. At least one production well is in the formation. A bottom portion of the production well is a sump in an underburden of the formation below the heated portion of the formation. Fluids from the heated portion of the formation are allowed to flow into the sump. A pump system has an inlet in the sump. A production conduit is coupled to the pump system. The production conduit is configured to transport fluids in the sump out of the formation.
The Government has certain rights in this invention pursuant to Agreement No. ERD-05-2516 between UT-Battelle, LLC, operating under prime contract No. DE-ACO5-000R22725 for the US Department of Energy and Shell Exploration and Production Company.