signals representative of these parameters to the controller 70 the controller 70 may be located downhole as shown in fig2 or may be placed at the surface in which signals are transmitted across the formation through wires or cables or wireless transmission such as telemetry an inlet sensor 72 is positioned at the inlet of the hydrocyclone separator 40 a first outlet sensor 74 is positioned in the first outlet conduit 44 and a second outlet sensor 76 is positioned in the second outlet conduit 46 in the embodiment shown in fig2 the sensors are connected to the controller 70 through wires 80 81 and 82 respectively it is understood that other communication techniques may be employed for example the sensors may also communicate with the controller 70 through telemetry thereby excluding the need for wires 80 81 and 82 sensor 94 is coupled to pump 52 and controller 70 through wires or telemetry and monitors the intake pressure at pump 52 the controller 70 produces controlling signals and provides the controlling signals to one or more control devices the control devices include the motor 56 a first control valve 90 positioned in the first outlet conduit 44 a second control valve 92 positioned in the second outlet conduit 46 an inlet control valve 93 positioned in the inlet of the separator 40 and pump 100 the first control valve 90 may be eliminated and flow through first conduit 44 may be controlled directly by controlling pump 100 through wire 84a alternatively pump 100 and first control valve 90 may be used in conjunction in the embodiment shown in fig2 the controller 70 is connected to the control devices through wires 83 84 85 87 and 84a.