Home – Home – Jornals – Journal of Mining Sciences 2025 number 3

Mathematical modeling investigates the influence of an underpump tubing string on the longitudinal vibration intensity in the oilwell tubing and pumping unit assembly during operation of an electric submersible pump (ESP). The use of the underpump tubing strings with a length of ¼ wavelength with a dominant frequency of longitudinal vibrations of ESP reduces the vibration rate at this frequency by 2-3 times, and the diameter of the underpump tubing string is of no importance. Such underpump tubing strings in producing oil wells can help improve reliability and service life of ESP. When an underpump tubing string is set on the well bottom and pressed to the casing string along a spiral line, the longitudinal vibrations of the underpump tubing string transform into variable side stresses which influence the casing string and the reservoir rocks in the bottomhole formation zone, while no increase in the longitudinal vibration rate takes place in the pumping unit. The working ESP with the underpump tubing string rest on the well bottom conditions continuous vibration effects on a pay zone in the course of the well operation, which improves permeability of rocks in the bottomhole formation zone.