It is shown that the primary cause of inefficient operation of multiphase pump-ejector systems installed in oil fields for combined oil and gas gathering is that not only associated (casing-head) gas, but also oil recovered incidentally with water enters the receiving chambers of jet apparatuses. Even under the current operation conditions, the power consumption at DNS-0122 Sofinskaya booster-type pumping plant can be reduced more than twofold by utilizing the existing infrastructure to the maximum and optimizing the flow diagrams of the pump-ejector system where the functions of submersible centrifugal pumps and jet apparatuses are separated. In future development, the pump-ejector system could be provided with an additional ejector, which will allow effective integration of straight-flow and circulatory schemes.