Abstract: A system for improving production of crude oil from an underground reservoir by the injection of treatment fluids includes a well casing, a production tube located within said well casing and defining therewith an annular space for receiving treatment fluids, a packer located within said annular space for isolating said annular space from a reservoir, a pump disposed in said production tube and having an inlet valve for receiving fluids to be pumped and a mixing shoe for mixing treatment fluids from said annular space with crude oil from said reservoir so as to form a substantially homogeneous mixture of said oil and said fluids in said production tube below said inlet valve of said pump.

Abstract: A down-hole separator for a production well drilled in a producing formation has a first tube having a first end and a second end, the first end being adapted for connection to an end of a production tubing of the production well, an outer annular space being defined between the first tube and a casing string of the production well; a second tube, having a smaller diameter then the first tube, and being disposed within the first tube, an inner annular space being defined between the second tube and the first tube, the second tube having an inlet end and an outlet end, the outlet end being turned at an angle relative to a longitudinal axis of the second tube and communicating with the outer annular space, the inlet end passing sealingly through the second end of the first tube to communicate with the producing formation, the first tube having perforations at a point below the outlet end of the second tube to allow communication between the outer annular space and the inner annular space.