The Management Strategy for Electrical Submersible Pump Low Performance in Large Oil Fields

Abstract The low performance of the electrical submersible pumps (ESP) in oil fields disturbs the electrical power system. Although there is no general model to predict ESP performance, doubts arise about the results achieved to evaluate this situation all this time. Lately, the system classified the problem as hydraulic and electric losses. Therefore, locating and quantifying ESP system losses is a determinable management task. In general, two different energy systems, the ESP hydraulics and natural crude oil reservoirs, are supposed to boost each other inside the well. The boosting depth had to be positioned below the bubble point pressure. This situation has decreased the limited ESP efficiency. This paper will propose a new plan to enhance those ESPs operating at low performance. To clarify and confirm this new method, two different Libyan oil reservoirs have been used for the new method in this study. The new method has been prepared through four program phases. Phase One: performance indicator, which ensures that the ESP performance indicator at the wellhead is operating on standard flowing measurements. Phase Two: minimized volumetric-hydraulic losses by maintaining as smooth a flowing stream (Pump-Well Head) as possible. Phase Three: adjusting the mechanical losses across the pump between intake pressure and discharge head pressure. Phase Four: unitizes the volumetric and mechanical products within the ESP's available pump efficiency to calculate the brake horsepower (BHP) and stages required. The results showed that the overall system efficiency between the engine system (BHP) and the surface electrical horsepower (HP) should be a ratio of 1:1 or smaller. The case studies showed obvious differences between the ESP design types (conventional, nodal, and the new design procedure), as well as between the two oil reservoirs. The improvement of the new design indicates that the loss calculations are the right procedure to understand the troubleshoot and maintain the whole system.