Abstract: A longstroke pumping apparatus for oil well pumping is provided with turnaround capability and more efficient operation by the use of a two section grooved capstan arrangement from which a flexible pumping cable extends down the well and a flexible counterweight cable extends to a counterweight in a counterweight well. The first section of the capstan from which the pumping cable extends has a basically constant diameter while the second section of the rotatable capstan from which the counterweight cable extends is formed from three contiguous interconnected portions. The central portion has a substantially constant diameter and the two end portions have respectively an effectively increasing diameter and an effectively decreasing diameter. Variations of the above basic arrangement are also described.

Abstract: In a rotating drum or winch type long stroke pumping unit in which the motor which powers the pumping unit operates only during the central portion of the pumping stroke, the motor is energized at the point of maximum load upon the pumping string during the upstroke and the point of minimum load on the downstroke. By precisely coordinating the energization of the motor with the load upon the pumping string detrimental oscillations in the pumping string are damped out.