A system and series of methods, which utilize Geopressured-Geothermal (GPGT) energy for the enhanced recovery of formation crude oil. The system is designed to interface with a conversion system which concentrates the GPGT brine while recovering H2O distillate and gas, e.g., as taught by Nitschke in U.S. Pat. Re. 36,282. The system promotes enhanced oil recovery (EOR) from an oil formation via steamflood and optional gas injection, powered by the GPGT gas and using the recovered H2O distillate for source water. The system optionally reuses the bulk of the injected EOR fluids via thermal regeneration and volume replenishing, alleviating disposal costs and environmental stresses. The system manages the concentrated GPGT brine byproduct by optionally producing solid salt for sale, flowing to an appropriate end-user, or disposing in a suitable subterranean formation.