Problems of Pumping Deep Wells

With the depletion of our older, and relatively shallow, oilfields and thenecessity for securing new production from deeper horizons, much attention isbeing given to the improvement of oil-well pumps in order that they mayfunction satisfactorily under the more difficult conditions imposed byincreased depth. Until recently, practically all of the world's petroleum wassecured from wells less than 3000 ft. deep, whereas horizons are now beingexplored to depths of from 5000 to 7000 ft. in some of the more prolificfields, and it seems probable that the greater part of the future supply mustcome from depths in excess of 3000 ft. While much of the early production in anew field is obtained by natural-flow methods, when the stimulus of high gaspressure fails, recourse must be had to some method of pumping. The perfectionof a pump capable of economically and efficiently lifting oil from depthsranging from 3000 to 7000 ft. is therefore a matter of prime importance to theoil-producing industry. This paper is offered as an estimate of the presentstate of development of the oil-well plunger pump and as a review of thegeneral principles involved in its operation in deep-well pumping. A design fora new type of oil-well pump embodying several novel features, is alsodescribed. Essential Parts of Oil-Well Plunger Pump The pump commonly used in lifting oil from wells in American practice is ofthe simple displacement type, in which a plunger equipped with a working, ortraveling, valve is given a vertical reciprocating motion in a stationaryworking barrel. The latter is suspended from the surface by tubing, submergedin the well fluid, and is equipped at its lower end with a stationary standingvalve; Figs. 1 and 2 illustrate two common types of oil-well pumps. The simplecup-leather packed plunger of Fig. 1 has its counterpart in the long, hollow, cylindrical, polished steel plunger of Fig. 2; otherwise the two types areidentical in the form and arrangement of their essential parts.