Heat dissipation of the Electrical Submersible Pump (ESP) installed in a subsea skid

Abstract

The recent development of Electrical Submersible Pump (ESP) in the skid, installed in the seabed downstream of the wellhead in an offshore oil production system, is an alternative to the conventional system with the set installed at the bottom of the producing well, facilitating interventions in case of failure. The pump is driven by an electric motor whose cooling must be efficient to ensure the continuity of its operation. The heat withdrawal is performed by the fluid produced. The purpose of this article is to understand the process of electric motor cooling to the single-phase and turbulent flow with convection heat transfer in an annular geometry, which represents the space formed between a capsule and the ESP in the Skid system motor. With this objective it is employed a Computational Fluid Dynamics (CFD) code to solve the governing equations of the turbulent heat transfer single-phase flow. The standard κ-ε model with improved wall function (Enhanced Wall Treatment) is used to closure turbulence problem. This study considered flow rates range of 2200–4200 m3/d (representing Reynolds numbers range of 27 000–133 000 approximately), Prandtl numbers 7–37, three configurations of different annular geometries, one concentric and two eccentric, together with the condition of the constant temperature on the motor surface (130 °C) and capsule (4 °C). The simulations are validated by comparing the Nusselt number in the developed region with the Gnielinski correlation. It is observed that if the constant heat flux condition were used, the motor temperature would have lower values at the beginning and larger at the end of the geometry. Therefore, the higher the Nusselt number, the greater the heat transfer, thus intensifying the cooling of the electric motor. In the eccentric geometry a momentum transfer from the lower to the upper annular region is observed, causing the Nusselt number present an angular variation. In eccentric geometries the flow develops in greater lengths, observing that the greater the eccentricity, the greater this length. Finally, for the ESP in the Skid system the use of an eccentric geometry is not adequate.

Analysis of Nucleation Time of Gas Hydrates in Presence of Paraffin During Mechanized Oil Production

“…This approach is grounded in differential equations of heat conduction, incorporating the heat transfer coefficient between the surrounding rock formations and the well's flow. The determination of this coefficient leverages field-derived data (14). The phenomenon of convective heat transfer in vertical gasliquid two-phase hydrocarbon flows has been examined (15,16), with laboratory experiments revealing the relationship between the heat transfer and the velocity and structure of the mixture.…”

“…Additionally, the impact of operating an electrical submersible pump (ESP) on the heat exchange dynamics between the pumped fluid and its surroundings warrants attention. Investigations (14,19) have delved into the thermal interactions between an active ESP unit and its immediate environment, proposing a model that accurately predicts the temperature variations of both the unit itself and the fluid in transit through and around the pump. Moreover, the processes of well killing and the injection of specialized fluids can induce cooling in the bottom hole zone and wellbore, potentially leading to the augmented formation of ARPD and gas hydrates within the well space.…”

Microstructure and Performance of Ni/TiN Coatings Deposited by Laser Melting Deposition on 40Cr Substrates

“…The 40Cr steel (GB/T17107-2018) is generally used for manufacturing the shaft of an electric submersible pump (ESP) [1]. However, during a long-term operation, the shaft of the ESP is prone to wear and corrosion due to sand particles, acid liquid, poor lubrication, and other factors [2][3][4]. Some repair methods, such as electrospark deposition, brushing electrodeposition, plasma arc deposition, and laser melting deposition can be used to refabricate the shaft when it is worn or corroded [5][6][7][8].…”

Influência da vazão de injeção sobre a uniformização do perfil de fluxo em poços horizontais

“…O petróleo é uma fonte de energia não-renovável, devido ao tempo necessário para sua formação e também à depleção e ao trapeamento no reservatório, ao mesmo tempo em que constitui a principal fonte da matriz energética mundial (British Petroleum, 2018). Além disso, as fontes renováveis não superam o petróleo em sua versatilidade e sua eficiência, as quais o tornam insubstituível na maioria das aplicações (Rigatto e Romero, 2018;Guidi e Romero, 2018;Araujo e Romero, 2019;Romero e Lima, 2019;Martins et al, 2020;Santos et al, 2020). Estes obstáculos são geralmente superados pelas empresas operadoras através da procura por novos campos e da busca pelo aumento da recuperação.…”