Artificial Lift
The oil industry uses the term lifting to refer to the process of vertically transporting fluids extracted from a reservoir, which must flow from the well bottom to the production facilities. Artificial Lift methods are used when the reservoir lacks sufficient energy to lift the fluids up to the surface or when the flow rate produced naturally is not economical.
Proper selection of an Artificial Lift method for a given production system is a strategic decision that involves evaluating reservoir characteristics, such as temperature, pressure, optimal production flow rate and fluid properties, and well characteristics, i.e., depth, slope, completion, and surface facilities.
Over the last 20 years, the ALFA group has been developing fundamental and applied studies in Artificial Lift, assisting the exploration of several oil fields. The experimental studies are performed in laboratory and pilot scale under flow-controlled conditions. The development of numerical approaches, and physical and empirical models has been paramount for the design of Artificial Lift systems.
a. ESP
Electrical Submersible Pump (ESP) is an important artificial lift method used in oil production. ESPs can provide high production flow rate, are flexible and can be installed in highly deviated wells, subsea deepwater wells, or directly on the seabed. ESPs supply energy to the oil and increase the flow rate in naturally flowing wells, and can even enable the production in pumping wells. The relevance of ESPs is highlighted by their wide range of application. It is estimated that ESPs are the second most used production method and the first considering the production volume worldwide.
The ALFA group has been developing studies applied to ESP and integrating its operation with viscous and ultra-viscous fluids, gas-liquid and liquid-liquid (emulsion) multiphase flows, among others. For multiphase pumping, the flow visualization is central to understanding the phase behavior. These studies employ state-of-the-art high-speed imaging techniques, Particle Image Velocimetry (PIV), and optical probes to measure population distribution (FBRM). These studies are focused on understanding and modeling the behavior of ESPs under real operating conditions, contributing to the dimensioning of real production systems.