Abstract: A standing valve which may be retrievably mounted in a well production tubing and will allow the maximum possible fluid flow and also allow the valve to be easily drained and retrieved through the well production tubing. The seal between the standing valve and the bottom hole assembly is located at or below the level of the seat and fluid from the top of the valve into the well is drained through the seat.

Abstract: A fluid operated pump system which includes power fluid supply means comprising either the annulus between well casing and production tubing, or a secondary tubing, and a production tubing, set in a well, the production tubing having a housing at the lower end with which the power fluid supply means communicates. A pump unit, including a fluid operated jet pump, is movable downwardly through the production tubing into the housing to a fixed location and maintained at the fixed location by the forces of gravity and friction. The pump is operable in the housing by operating fluid under pressure supplied through the power fluid supply means to pump fluid from the well into the production tubing. A cavity is provided at the lower end of the pump unit between two balanced seals. The cavity communicates with the power fluid supply means and with the fluid operated jet pump. Power fluid introduced into the cavity causes no net force to be exerted on the pump unit.