Abstract: A control system for an in-well pump for recovery of hydrocarbons which are lighter than water. Two electrical probes and a float switch are used to control the automatic raising and lowering of the pump within the well to always maintain its input within the hydrocarbon layer. The pump is also controlled so that it only operates when its input is within the hydrocarbons to assure that it does not pump water and that it is not operated in air.

Abstract: An in-well separator and recovery device for liquids which are heavier than water. A closed top container in the well circulates liquid through it, drawing liquid into its lower region and deflecting the liquid downward so that the heavier liquid settles to the bottom of the container from where it is pumped to the surface. Water is pumped from the top of the container directly back into the well. The pumps are controlled by sensing the water to pollution interface in the container and shutting down each pump before it pumps the inappropriate liquid.

Abstract: An automatic well skimmer for removal of floating contaminates and oil and gasoline seepage from water wells. A cylindrical well bailer is lowered and raised by means of a motor driven cable hoist programmed to lower the bailer in small increments after detecting the liquid level and to lift the bailer before it is completely filled with liquid. When lifted to the surface the liquid is dumped from the bailer and the bailer is returned to the well. The timing of the controls can be varied to permit skimming at rates comparable to the seepage of hydrocarbons into the well and the bailer can be stored below ground in the well between cycles to prevent freezing of the unloading mechanism.