History
The walking-beam , sucker-rod method of pumping has been in use since at least 476 A.D. When the Egyptians used the principle for drawing water, and has been used in the petroleum industry since the days of Drake's discovery in Pennsylvania.
In comparison, hydraulic pumping as it exists today is a brand new method of raising subsurface fluids to the surface. Even compared to gas lift, which was first used to lift oil from some wells in Pennsylvania in 1846.
Faucett first used the basic principle of hydraulic pumping to recover oil in 1875. The Faucett bottom hole pump was a steam operated device, that required a very large diameter hole to operate. Because of this diametrical requirement, the Faucett pump found no real commercial application in the oil patch.
In the 1920's, increasing well depths brought back the concept of hydraulically retrieving production. The first serious hydraulic installation was set up on March 10, 1932 in Inglewood, California. Since 1932, several thousands of wells have been, and to this day are still being produced with hydraulic pumps.
The number of new hydraulic installations is increasing yearly. As the volume, weight, depth, and well deviation of producing wells continues to increase at a rapid pace.
Pascal's Law, which states: "Pressure applied at any point upon a contained liquid is transmitted with equal intensity to every portion of the fluid and the walls of the containing vessel.", is the fundamental principle used in subsurface hydraulic pumping. Application of this principle makes it possible to transmit pressure from a central surface location through liquid filled tubing to any number of points below the surface in a well. The pressurized liquid sent down the power fluid tubing lines is directed to a subsurface engine, which is made to reciprocate and operate a mechanically coupled plunger pump.
It has always been recognized that the weak link, and ultimate limiting factor, in sucker-rod pumping systems is the sucker-rod itself. The thousands of feet of rods needed to transmit the reciprocating motion from the surface to the bottom hole pump just cannot be made strong enough to lift high loads from great depths. Even with the high strength Class 'D' rods with tapered string designs we have today can't be expected to lift more than a 40,000 lb. peak load without over stressing the top rods causing failures. In a rod system, the rods must not only lift the well fluid on every stoke, but also lift up to 15 tons of steel. The dead weight of the rods themselves plus the dynamics of cyclic loading imposes serious limitations on pumping depths and associated production volumes.
As producing horizons become increasingly deeper, the problem of a rapid drop off in maximum volume and efficiency with increasing depth of lift for high volume centrifugal pumping imposes a serious limitation on the application of the electric submersible pump to wells.
Gas lifting of well fluids is restricted by a minimum bottom hole producing pressure, which increases with increasing depth and volume, and with decreasing gas-oil ratio (GOR).