Paper: Pumping Heavy Loads With The Mark II

The ever-increasing demand for additional energy sources and hydrocarbon products has pushed the search for new petroleum reserves to ever greater depths. As depths increased and well loads became successively heavier, the need also arose for higher capacity and more effective artificial lift systems. In the past, the simplicity, efficiency, and reliability of the beam pumping unit have made it a favorite with many operators, when pumping loads were light to medium. But when large volumes were to be lifted from deep wells, or massive volumes from shallow to medium depths, this historic system was often incapable of producing the required fluid, and other artificial lift methods had to be employed. Challenged by these limitations, designers of the various components of the beam pumping system redoubled their efforts to increase beam pumping capacity by upgrading and improving: (1) bottomhole pumps, (2) pumping units, (3) prime movers, and especially (4) sucker rods. One beam pumping innovation, which has now been in service for some years, is the so-called Mark II unit (Fig. 1) made up of the traditional components of walking beam, post, cranks, horsehead, pitman, etc., but rearranged to form a reversed-type geometry, with certain unique functional and kinematic properties.