Abstract: A hydraulic pump apparatus (35) for a well assembly (36) including a rigid, elongated tubular casing (37). extending into a formation producing production fluid. The hydraulic pump apparatus (35) including an elongated tube (40) and a bottom-hole assembly (42) mounted to a lower end of the tube (40). The bottom-hole assembly (42) includes an outwardly facing sealing surface (54). A "free" jet pump assembly (55) is included having a pump body (56) formed for sliding receipt in the tube (40) and the pump receiving passage (49). The pump body (56) includes a lower seal (60) mounted to an inwardly facing surface (62) of the jet pump assembly (55) for sealing engagement with the outwardly facing sealing surface (54) of the discharge port (51) to permit discharge of exhausted production fluid from the jet pump assembly (55) through the discharge port (51).