Apparauts for fluid pumping

Abstract

A fluid balanced hydraulic pump has a support tower that can be mounted over a well. At least one cylinder assembly is pivotally mounted within the support tower. A prime mover provides hydraulic fluid to the at least one cylinder assembly through a wedge spool control valve that provides precise speed control with minimal maintenance requirements. Stroke speed can be easily and quickly adjusted without the need for expensive, troublesome or complicated electronic equipment.

What is claimed: 
     
         1 . A reciprocating pumping apparatus for pumping fluids from a downhole pump in a well comprising:
 a. a support frame mounted to said well;   b. at least one hydraulic cylinder assembly having a first end and a second end mounted within said support frame in substantially axial alignment with said well, wherein said first end is connected to said downhole pump and said second end is connected to said support frame;   c. a hydraulic pump for supplying hydraulic fluid to said at least one hydraulic cylinder assembly;   d. a wedge spool control valve disposed between said hydraulic pump and said at least one hydraulic cylinder assembly;   e. an upper switch disposed in said support frame, wherein said upper switch stops pumping by said hydraulic pump when said at least one cylinder assembly is retracted a predetermined distance; and   f. a lower switch disposed in said support frame, wherein said lower switch commences pumping by said hydraulic pump when said at least one cylinder assembly is extended a predetermined distance.