A prediction model for a new deep-rod pumping system

The side-flow pump is presented for increasing the setting depth of sucker rod pumping system, which adopts a special structure of side-flow valve, ladder-type solid plunger and breathing hole. By transferring the load of liquid column to the tubing on the upstroke, the new pump achieves a smaller polished rod load. On the basis of in-depth study of the pump, this paper provides a brief formula of the static polished rod load. Assuming the tubing is anchored, a new one-dimensional vibration model of sucker rod pumping system is built, which takes into account the structure of the side-flow pump. Then a mathematical model is used to design the sucker rod pumping system of Well TKN-1, with a setting depth of 4716 m. The results of dynamometer analysis show that mathematical model of side-flow pumping system and its computer programs can successfully model deep rod string performance. The rod pumping system of Well TKN-1 has operated trouble-free for 8 months. The knowledge gained gives confidence for additional future applications.