Abstract: A process has been invented to inject and withdraw water from an aquifer for purposes of energy storage under some abnormal conditions. This transfer system is for thermal energy storage applications where the transfer water pressure is higher than the normal aquifer pressure at the point of withdrawal or injection. Applications include systems where water temperatures are in excess of the normal boiling point and the water must be pressurized, to prevent boiling and/or and where an aquifer has a water head well below ground level creating excess pressure from the column of water from the surface to the acquifer. Water is injected through a process which reduces the pressure at the aquifer to the pressure required for injecting the correct water flow rate. In recovering the thermal energy, or withdrawal, the system provides the proper pressurization at aquifer level to the required pressure.