A Fit-For-Purpose ESP Technical Solution Enables 17% Production Increase in Complex Reservoirs in Mature Fields in Ecuador

Abstract

A fit-for-purpose electrical submersible pump (ESP) technical solution, based on a combination of pump types and an innovative extended gas-handling device resulted a production increase of 17% in four mature fields in Ecuador. The extended gas-handling device enabled a superior performance of ESP systems to decrease downhole parameter fluctuations normally observed in challenging production conditions to improve oil production. Historically, ESP operations in mature fields in Ecuador have posed extremely demanding conditions, where reservoir depletion generates lower static and flowing pressures that are typically associated with an increment in free-gas content in the produced fluid. Low flow rates, high lifting requirements, and high gas content degrade ESP performance and reliability while complying with field economics. This innovative ESP technical approach improves fluid hydraulics through the pump by combining a newly developed extended gas-handling device with proper selection of pump stage models to avoid production losses due to gas blockage, leading to an increase of pressure drawdowns and the maximization of flow rates. Additionally, when the reservoir has had a fracturing job to improve its productivity, the ESP selection process becomes even more challenging. Therefore, this ESP configuration incorporates a robust technology to face abrasive conditions, and flow rates are thoroughly controlled during the well's initial production phase to mitigate excessive migration of proppant into the pump. The technical solution developed has helped to increase production and improve the equipment reliability. On the 47 wells where this technology was successfully adopted, a 17% increase in oil production was observed and was attributed to the system's capacity to maximize reservoir drawdowns, with intake pressures as low as to 150 psi, while maintaining stead operation in gassy conditions. The enhanced equipment performance obtained with this technology contributed to a reduction in the number of ESP failures having as root cause low productivity, which decreased from 34 in 2019–2020 to 16 in 2021–2022 with zero ESP-related failures recorded among the 47 wells where this technology was installed. This innovative ESP configuration has emerged as a pioneering solution in the region to fulfill challenging production conditions in mature fields where a cost-effective solution is required. Furthermore, it opens a new spectrum to maximize oil production in mature fields by expanding the currently understood technical boundaries for ESP operation in low-flow gassy applications.