Paper: History, Background, and Rationale of the Mark II, Beam Type, Oil Field Pumping Unit

The Conventional beam pumping unit, a Class I lever system, was used almost exclusively in artificial lift applications from the 1700's until the late 1920"s. At that time, a "reversed" Conventional geometry design (Class III lever system), called an Air Balance unit because of its pneumatic counterbalance system, made its appearance. Later, in the mid 19503, a second, Class III lever system, or "reversed" geometry unit, was introduced and named the Mark II. Like the Air Balance unit, the Mark II had some performance features different from those of the traditional Conventional unit, but used similar rotating counterweights instead of the pneumatic arrangement of the Air Balance unit. The following paper will discuss some of the unique performance concepts of the Mark II design, and the background and rationale behind their development.