Paper: Hydraulic Pumping Phase III

Phase I for the hydraulic pumping method of artificial lift was the initial development of the first commercially successful hydraulic pumping installation in 1932. Phase II followed with the introduction of the "free pump" in 1948. Phase III covers the relatively recent development of the unitized, skid-mounted Power Fluid Conditioning Unit which was conceived in 1969 and placed on the market in 1970. The acceptance of the concept of using a PFCU for taking well fluid and making it suitable for power fluid had resulted primarily from overcoming the disadvantages of the established central system concept - specifically, the high cost of treating and storing power oil combined with cost of long, high-pressure power oil lines. The "Unidraulic" Hydraulic Pumping System eliminates these disadvantages by moving the power fluid system back to the well site. The Power Fluid Conditioning Unit removes solids from the produced well fluid with a cyclone separator. The cyclone converts the pressure energy of the fluid into centrifugal force to increase the settling velocity of the suspended solids. These solids are carried by the force to the discharge point at the bottom of the cone. The liquid phase, being lighter, moves upward in the cone as a spiraling vortex to the liquid discharge connection at the top of the cyclone. Solids-free power fluid, either water or oil, from the reservoir provides suction to the multiplex pump which returns the power fluid at the required pressure to the wellhead to again operate the subsurface production unit to start the lift cycle all over again. Lease treating facilities are needed to process and treat only that volume of oil, water or gas that is actually produced from the well; the same as for a sucker rod pumping well. Therefore, well testing procedure is performed exactly as a sucker rod pumping well.