Abstract: A turbine impeller pump particularly for use in a geothermal pumping system has a casing with a hollow cylindrical stator or axle fixedly connected in the longitudinal axis thereof which stator or axle defines a flow passage for motive fluid and enables a rotor assembly to be rotatably mounted thereon. The rotor has spaced composite impellers which lie in assembled position in medially disposed pumping chambers in the casing having a suction inlet for fluid to be pumped and a discharge outlet for pumped fluid. The rotor further has first and second multi-stage axial flow driving assemblies disposed on opposite sides of the spaced composite impellers so that the motive fluid for driving the same can be passed to the respective adjacent composite impellers and delivered with the fluid being pumped.